Android: Luyện toán

App này có liên quan đến kỹ thuật Content Provider.

File activity_title.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <TextView
    android:text="Cuộc thi tính toán"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView20"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.101"
    android:textSize="36sp" android:textColor="#FF1100"
    android:textStyle="bold"/>
  <Button
    android:text="BẮT ĐẦU"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/Start"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.499"
    android:textStyle="bold|italic"
    android:textSize="36sp"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_start.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/lv10"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.894"
    app:layout_constraintVertical_bias="0.745"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/lv9"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.733"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/lv8"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.08"
    app:layout_constraintVertical_bias="0.733"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/lv1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.08"
    app:layout_constraintVertical_bias="0.202"
    android:onClick="show"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/lv5"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.699"
    app:layout_constraintVertical_bias="0.399"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/lv7"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.699" 
    app:layout_constraintVertical_bias="0.566"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/lv6"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.297" 
    app:layout_constraintVertical_bias="0.566"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/lv3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.95"
    app:layout_constraintVertical_bias="0.228"/>
  <TextView
    android:text="CHOOSE LEVEL"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/textView"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent" 
    android:textColor="#F44336" 
    android:textSize="24sp"
    app:layout_constraintHorizontal_bias="0.497" 
    app:layout_constraintVertical_bias="0.045"/>
  <Button
    android:text="Level 1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/Level1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.049"
    app:layout_constraintVertical_bias="0.125" 
    android:textColor="#E91E63" 
    android:textSize="24sp"/>
  <Button
    android:text="Level 4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level4"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    app:layout_constraintHorizontal_bias="0.277"
    app:layout_constraintVertical_bias="0.3" 
    android:textColor="#3F51B5" android:textSize="24sp"/>
  <Button
    android:text="Level 5"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level5"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    app:layout_constraintHorizontal_bias="0.732"
    app:layout_constraintVertical_bias="0.3" 
    android:textColor="#2196F3"
    android:textSize="24sp"/>
  <Button
    android:text="Level 6"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level6"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.277"
    app:layout_constraintVertical_bias="0.472" 
    android:textColor="#00BCD4" 
    android:textSize="24sp"/>
  <Button
    android:text="Level 7"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/level7"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.472" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.732"
    android:textColor="#009688"
    android:textSize="24sp"/>
  <Button
    android:text="Level 8"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level8"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    app:layout_constraintHorizontal_bias="0.046"
    app:layout_constraintVertical_bias="0.639"
    android:textColor="#4CAF50"
    android:textSize="24sp"/>
  <Button
    android:text="LEVEL 2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.128" 
    android:textSize="24sp" 
    android:textColor="#E91E63"/>
  <Button
    android:text="LEVEL 3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level3"
    app:layout_constraintBottom_toBottomOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintHorizontal_bias="0.965"
    app:layout_constraintVertical_bias="0.127"
    android:textSize="24sp"
    android:textColor="#9C27B0"/>
  <Button
    android:text="LEVEL 9"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level9"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.639" 
    android:textSize="24sp" 
    android:textColor="#FFC107"/>
  <Button
    android:text="LEVEL 10"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/level10"
    android:textSize="24sp"
    app:layout_constraintBottom_toBottomOf="parent" 
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.964" 
    app:layout_constraintVertical_bias="0.639"
    android:textColor="#FFEB3B"/>
  <Button
    android:text="BACK"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.976" 
    android:textSize="18sp"
    android:textColorHighlight="#FF1100"
    android:textColor="#FF0000"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/lv4"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.297" 
    app:layout_constraintVertical_bias="0.399"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/lv2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent" 
    android:textSize="12sp"
    app:layout_constraintHorizontal_bias="0.498" 
    app:layout_constraintVertical_bias="0.212"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level1.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context=".level1Activity">
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.876"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.817"
    app:layout_constraintVertical_bias="0.184"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.174"
    app:layout_constraintVertical_bias="0.184"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/cong"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView4"
    android:textSize="36sp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.184"/>
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.072"
    app:layout_constraintVertical_bias="0.023"
    android:textSize="30sp"
    android:textColor="#EF1505"
    android:text="@string/score"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.497"
    app:layout_constraintVertical_bias="1.0"
    android:textSize="24sp"
    android:textStyle="bold"
    android:textColor="#FF0000"/>
  <TextView
    android:text="@string/level1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView10"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#E91E63"
    android:textStyle="bold"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level2.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.904"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/level2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView11"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#9C27B0"
    android:textStyle="bold"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/score"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp" android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
  <TextView
    android:text="@string/tru"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView6"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.49"
    app:layout_constraintVertical_bias="0.256"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level3.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.904"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/level3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView12"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#673AB7"
    android:textStyle="bold"/>
  <TextView
    android:text="@string/nhan"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.256"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
  <TextView
    android:text="@string/score"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level4.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.904"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/level4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView13"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#3F51B5"
    android:textStyle="bold"/>
  <TextView
    android:text="@string/chia"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.256"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
  <TextView
    android:text="@string/score"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level5.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.904"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/level5"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView14"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#2196F3"
    android:textStyle="bold"/>
  <TextView
    android:text="@string/score"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
  <TextView
    android:text="@string/cong"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView8"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.256"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level6.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent" 
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.876"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/level6"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView15"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#03A9F4"
    android:textStyle="bold"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold" android:textSize="24sp"
    android:textColor="#FF0000"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/tru"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView5"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.49"
    app:layout_constraintVertical_bias="0.256"/>
  <TextView
    android:text="@string/score"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level7.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.876"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/level7"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView16"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#00BCD4"
    android:textStyle="bold"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/chia"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView7"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.256"/>
  <TextView
    android:text="@string/score"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level8.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.876"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="@string/level8"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView17"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#009688"
    android:textStyle="bold"/>
  <TextView
    android:text="@string/number2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
  <TextView
    android:text="@string/score"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
  <TextView
    android:text="@string/nhan"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView9"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.256"/>
  <TextView
    android:text="@string/number1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
  <Button
    android:text="@string/back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level9.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.876"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="Level 9"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView18"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#009688"
    android:textStyle="bold"/>
  <TextView
    android:text="TextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
  <TextView
    android:text="0"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.256"
    android:id="@+id/textView"/>
  <TextView
    android:text="TextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
  <Button
    android:text="back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File activity_level10.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.111"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintVertical_bias="0.614"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/c3"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.876"
    app:layout_constraintVertical_bias="0.614"/>
  <TextView
    android:text="Level 10"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView19"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintVertical_bias="0.08"
    android:textSize="36sp"
    android:textColor="#009688"
    android:textStyle="bold"/>
  <Button
    android:text="back"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/back"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.994"
    android:textStyle="bold"
    android:textSize="24sp"
    android:textColor="#FF0000"/>
  <TextView
    android:text="TextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.746"
    app:layout_constraintVertical_bias="0.256"
    android:textSize="36sp"/>
  <TextView
    android:text="0"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/score"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="30sp"
    android:textColor="#FF0000"
    app:layout_constraintHorizontal_bias="0.022"
    app:layout_constraintVertical_bias="0.043"/>
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textView"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:textSize="36sp"
    app:layout_constraintHorizontal_bias="0.499"
    app:layout_constraintVertical_bias="0.256"/>
  <TextView
    android:text="TextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/s1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintHorizontal_bias="0.221"
    app:layout_constraintVertical_bias="0.255"
    android:textSize="36sp"/>
</androidx.constraintlayout.widget.ConstraintLayout>

File ScoreProvider.java:

package v1study.com.luyentoan;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.Context;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.content.ContentUris;
import android.text.TextUtils;

import java.util.HashMap;

public class ScoreProvider extends ContentProvider {
  static final String PROVIDER_NAME = "v1study.com.provider.Scores";
  static final String URL = "content://" + PROVIDER_NAME + "/scores";
  static final Uri CONTENT_URI = Uri.parse(URL);

  static final String _ID = "_id";
  static final String SCORE = "score";

  private static HashMap<String, String> SCORES_MAP;

  static final int SCORES = 1;
  static final int SCORE_ID = 2;

  static final UriMatcher uriMatcher;

  static {
    uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
    uriMatcher.addURI(PROVIDER_NAME, "scores", SCORES);
    uriMatcher.addURI(PROVIDER_NAME, "scores/#", SCORE_ID);
  }

  private SQLiteDatabase sqLiteDatabase;
  static final String DATABASE_NAME = "Scores";
  static final String SCORES_TABLE_NAME = "scores";
  static final int DATABASE_VERSION = 1;
  static final String CREATE_DB_TABLE =
    "create table "
      + SCORES_TABLE_NAME
      + "(_id integer primary key autoincrement,score integer)";

  @Override
  public boolean onCreate() {
    Context context = getContext();
    DatabaseHelper databaseHelper = new DatabaseHelper(context);
    sqLiteDatabase = databaseHelper.getWritableDatabase();
    return sqLiteDatabase != null;
  }

  @Override
  public Cursor query(Uri uri, String[] strings, String s, String[] strings1, String s1) {
    SQLiteQueryBuilder sqLiteQueryBuilder = new SQLiteQueryBuilder();
    sqLiteQueryBuilder.setTables(SCORES_TABLE_NAME);
    switch (uriMatcher.match(uri)) {
      case SCORES:
        sqLiteQueryBuilder.setProjectionMap(SCORES_MAP);
        break;
      case SCORE_ID:
        sqLiteQueryBuilder.appendWhere(_ID + "=" + uri.getPathSegments().get(1));
        break;
      default:
        throw new IllegalArgumentException("Unknown URI " + uri);
    }
    if (s1 == null || s1.equals("")) {
      s1 = SCORE;
    }
    Cursor cursor = sqLiteQueryBuilder.query(sqLiteDatabase, strings, s, strings1, null, null, s1);
    cursor.setNotificationUri(getContext().getContentResolver(), uri);
    return cursor;
  }

  @Override
  public String getType(Uri uri) {
    switch (uriMatcher.match(uri)) {
      case SCORES:
        return "vnd.android.cursor.dir/vnd/example.scores";
      case SCORE_ID:
        return "vnd.android.cursor.item/vnd.example.scores";
      default:
        throw new IllegalArgumentException("Unsupported URI: " + uri);
    }
  }

  @Override
  public Uri insert(Uri uri, ContentValues contentValues) {
    long rowID = sqLiteDatabase.insert(SCORES_TABLE_NAME, "", contentValues);
    if (rowID > 0) {
      Uri _uri = ContentUris.withAppendedId(CONTENT_URI, rowID);
      getContext().getContentResolver().notifyChange(_uri, null);
      return _uri;
    }
    throw new SQLException("Fail to ad a record into " + uri);
  }

  @Override
  public int delete(Uri uri, String s, String[] strings) {
    int count;
    switch (uriMatcher.match(uri)) {
      case SCORES:
        count = sqLiteDatabase.delete(SCORES_TABLE_NAME, s, strings);
        break;
      case SCORE_ID:
        String id = uri.getPathSegments().get(1);
        count = sqLiteDatabase.delete(SCORES_TABLE_NAME,
          _ID + "=" + id + (!TextUtils.isEmpty(s) ? " and (" + s + ")" : ""), strings);
        break;
      default:
        throw new IllegalArgumentException("Unknown URI: " + uri);
    }
    getContext().getContentResolver().notifyChange(uri, null);
    return count;
  }

  @Override
  public int update(Uri uri, ContentValues contentValues, String s, String[] strings) {
    int count;
    switch (uriMatcher.match(uri)) {
      case SCORES:
        count = sqLiteDatabase.update(SCORES_TABLE_NAME, contentValues, s, strings);
        break;
      case SCORE_ID:
        count = sqLiteDatabase.update(SCORES_TABLE_NAME, contentValues, _ID + "=" + uri.getPathSegments().get(1)
          + (!TextUtils.isEmpty(s) ? " and (" + s + ")" : ""), strings);
        break;
      default:
        throw new IllegalArgumentException("Unknown URI: " + uri);
    }
    getContext().getContentResolver().notifyChange(uri, null);
    return count;
  }

  private static class DatabaseHelper extends SQLiteOpenHelper {
    DatabaseHelper(Context context) {
      super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
      sqLiteDatabase.execSQL(CREATE_DB_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
      sqLiteDatabase.execSQL("drop table if exists " + SCORES_TABLE_NAME);
    }
  }
}

File TitleActivity.java:

package v1study.com.luyentoan;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import androidx.appcompat.app.AppCompatActivity;

public class TitleActivity extends AppCompatActivity {
  Button Start;

  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_title);
    getViews();
    Start.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(TitleActivity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }

  private void getViews() {
    Start = findViewById(R.id.Start);
  }
}

File StartActivity.java:

package v1study.com.luyentoan;

import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;

public class StartActivity extends AppCompatActivity {
  Button Level1, level2, level3, level4, level5, level6, level7, level8, level9, level10, back;
  Button lv1, lv2, lv3, lv4, lv5, lv6, lv7, lv8, lv9, lv10;

  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_start);
    getViews();
    getScores();

    Level1.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level1Activity.class);
        startActivity(intent);
      }
    });
    level2.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level2Activity.class);
        startActivity(intent);
      }
    });
    level3.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level3Activity.class);
        startActivity(intent);
      }
    });
    level4.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level4Activity.class);
        startActivity(intent);
      }
    });
    level5.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level5Activity.class);
        startActivity(intent);
      }
    });
    level6.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level6Activity.class);
        startActivity(intent);
      }
    });
    level7.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level7Activity.class);
        startActivity(intent);
      }
    });
    level8.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level8Activity.class);
        startActivity(intent);
      }
    });
    level9.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level9Activity.class);
        startActivity(intent);
      }
    });
    level10.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, Level10Activity.class);
        startActivity(intent);
      }
    });
    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(StartActivity.this, TitleActivity.class);
        startActivity(intent);
      }
    });
  }

  private void getScores() {
    Cursor cursor = getContentResolver().query(ScoreProvider.CONTENT_URI, null, null, null, null);
    if (cursor == null) {//Lỗi không kết nối được với DB
      //android.util.Log.e("DB", "Lỗi kết nối DB");
      Toast.makeText(StartActivity.this, "Error", 3000).show();
    } else if (cursor.getCount() == 0) {
      Toast.makeText(StartActivity.this, "Chưa có bản ghi", 5000).show();
      addScores();
    } else {
      cursor.moveToFirst();
      lv10.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv9.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv8.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv7.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv6.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv5.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv4.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv3.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv2.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
      if (cursor.moveToNext())
        lv1.setText(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
    }
  }

  private void addScores() {
    Toast.makeText(StartActivity.this, "Tiến hành thêm bản ghi", 3000).show();
    ContentValues contentValues = new ContentValues();
    contentValues.put(ScoreProvider.SCORE, 0);
    for (int i = 0; i < 10; i++) {
      getContentResolver().insert(ScoreProvider.CONTENT_URI, contentValues);
    }
    lv1.setText("0");
    lv2.setText("0");
    lv3.setText("0");
    lv4.setText("0");
    lv5.setText("0");
    lv6.setText("0");
    lv7.setText("0");
    lv8.setText("0");
    lv9.setText("0");
    lv10.setText("0");
  }

  private void getViews() {
    Level1 = findViewById(R.id.Level1);
    level2 = findViewById(R.id.level2);
    level3 = findViewById(R.id.level3);
    level4 = findViewById(R.id.level4);
    level5 = findViewById(R.id.level5);
    level6 = findViewById(R.id.level6);
    level7 = findViewById(R.id.level7);
    level8 = findViewById(R.id.level8);
    level9 = findViewById(R.id.level9);
    level10 = findViewById(R.id.level10);
    back = findViewById(R.id.back);
    lv1 = findViewById(R.id.lv1);
    lv2 = findViewById(R.id.lv2);
    lv3 = findViewById(R.id.lv3);
    lv4 = findViewById(R.id.lv4);
    lv5 = findViewById(R.id.lv5);
    lv6 = findViewById(R.id.lv6);
    lv7 = findViewById(R.id.lv7);
    lv8 = findViewById(R.id.lv8);
    lv9 = findViewById(R.id.lv9);
    lv10 = findViewById(R.id.lv10);
  }
}

File Level1Activity.java:

package v1study.com.luyentoan;

import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class Level1Activity extends AppCompatActivity {
  TextView s1, s2, score;
  Button c1, c2, c3, back, lv1;
  int score1;
  int a;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level1);
    getView();
    score1 = getScore();
    score.setText(score1 + "");
    develop();
  }

  private int getScore() {
    Cursor cursor = getContentResolver().query(ScoreProvider.CONTENT_URI, null, null, null, null);
    cursor.moveToLast();
    return Integer.parseInt(cursor.getString(cursor.getColumnIndex(ScoreProvider.SCORE)));
  }

  void getView() {
    s1 = findViewById(R.id.s1);
    s2 = findViewById(R.id.s2);
    c1 = findViewById(R.id.c1);
    c2 = findViewById(R.id.c2);
    c3 = findViewById(R.id.c3);
    lv1 = findViewById(R.id.lv1);
    score = findViewById(R.id.score);
    back = findViewById(R.id.back);
  }

  void addScore() {
    score1++;
    score.setText(score1 + "");
    updateScore();
  }

  void deScore() {
    if (score1 > 0) {
      score1--;
      updateScore();
    }
    score.setText(score1 + "");
  }

  void develop() {
    final Random random = new Random();
    s1.setText(random.nextInt(10) + "");
    s2.setText(random.nextInt(10) + "");
    a = random.nextInt(3);
    final int sum = (Integer.parseInt(s1.getText().toString()) + Integer.parseInt(s2.getText().toString()));
    if (a == 1) {
      c2.setText(sum + "");
    } else {
      c2.setText((sum + 2) + "");
    }
    if (a == 0) {
      c1.setText(sum + "");
    } else {
      c1.setText((sum + 5) + "");
    }
    if (a == 2) {
      c3.setText(sum + "");
    } else {
      c3.setText((sum + 4) + "");
    }
    c2.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 1) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }

    });

    c1.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 0) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });

    c3.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 2) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });

    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(Level1Activity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }

  public void updateScore() {
    Uri uriUpdate = ContentUris.withAppendedId(ScoreProvider.CONTENT_URI, 1);
    ContentValues contentValues = new ContentValues();
    contentValues.put(ScoreProvider.SCORE, score1);
    getContentResolver().update(uriUpdate, contentValues, null, null);
  }
}

File Level2Activity.java:

package v1study.com.luyentoan;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class Level2Activity extends AppCompatActivity {
  TextView s1, s2, score;
  Button c1, c2, c3, back;
  int score1;
  int a;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level2);
    getView();
    score1 = 0;
    develop();
  }

  void getView() {
    s1 = findViewById(R.id.s1);
    s2 = findViewById(R.id.s2);
    c1 = findViewById(R.id.c1);
    c2 = findViewById(R.id.c2);
    c3 = findViewById(R.id.c3);
    score = findViewById(R.id.score);
    back = findViewById(R.id.back);
  }

  void addScore() {
    score1++;
    score.setText(score1 + "");
  }

  void deScore() {
    if (score1 > 0) {
      score1--;
    }
    score.setText(score1 + "");
  }

  void develop() {
    final Random random = new Random();
    do {
      s1.setText(random.nextInt(20) + "");
      s2.setText(random.nextInt(20) + "");
    } while (!(Integer.parseInt(s1.getText().toString()) - Integer.parseInt(s2.getText().toString()) >= 0));
    a = random.nextInt(3);
    final int sum = (Integer.parseInt(s1.getText().toString()) - Integer.parseInt(s2.getText().toString()));
    if (a == 1) {
      c2.setText(sum + "");
    } else {
      c2.setText((sum + 2) + "");
    }
    if (a == 0) {
      c1.setText(sum + "");
    } else {
      c1.setText((sum + 5) + "");
    }
    if (a == 2) {
      c3.setText(sum + "");
    } else {
      c3.setText((sum + 4) + "");
    }
    c2.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 1) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }

    });
    c1.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 0) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    c3.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 2) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(Level2Activity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }
}

File Level3Activity.java:

package v1study.com.luyentoan;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class Level3Activity extends AppCompatActivity {
  TextView s1, s2, score;
  Button c1, c2, c3, back;
  int score1;
  int a;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level3);
    getViews();
    score1 = 0;
    develop();
  }

  void getViews() {
    s1 = findViewById(R.id.s1);
    s2 = findViewById(R.id.s2);
    c1 = findViewById(R.id.c1);
    c2 = findViewById(R.id.c2);
    c3 = findViewById(R.id.c3);
    score = findViewById(R.id.score);
    back = findViewById(R.id.back);
  }

  void addScore() {
    score1++;
    score.setText(score1 + "");
  }

  void deScore() {
    if (score1 > 0) {
      score1--;
    }
    score.setText(score1 + "");
  }

  void develop() {
    final Random random = new Random();
    s1.setText(random.nextInt(10) + "");
    s2.setText(random.nextInt(10) + "");
    a = random.nextInt(3);
    final int sum = (Integer.parseInt(s1.getText().toString()) * Integer.parseInt(s2.getText().toString()));
    if (a == 1) {
      c2.setText(sum + "");
    } else {
      c2.setText((sum + 2) + "");
    }
    if (a == 0) {
      c1.setText(sum + "");
    } else {
      c1.setText((sum + 5) + "");
    }
    if (a == 2) {
      c3.setText(sum + "");
    } else {
      c3.setText((sum + 4) + "");
    }
    c2.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 1) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }

    });
    c1.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 0) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    c3.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 2) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(Level3Activity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }
}

File Level4Activity.java:

package v1study.com.luyentoan;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class Level4Activity extends AppCompatActivity {
  TextView s1, s2, score;
  Button c1, c2, c3, back;
  int score1;
  int a, tu, mau, sum;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level4);
    getViews();
    score1 = 0;
    develop();
  }

  void getViews() {
    s1 = findViewById(R.id.s1);
    s2 = findViewById(R.id.s2);
    c1 = findViewById(R.id.c1);
    c2 = findViewById(R.id.c2);
    c3 = findViewById(R.id.c3);
    score = findViewById(R.id.score);
    back = findViewById(R.id.back);
  }

  void addScore() {
    score1++;
    score.setText(score1 + "");
  }

  void deScore() {
    if (score1 > 0) {
      score1--;
    }
    score.setText(score1 + "");
  }

  void develop() {
    final Random random = new Random();
    mau = random.nextInt(10);
    s2.setText(mau + "");
    tu = mau * random.nextInt(3);
    s1.setText(tu + "");
    a = random.nextInt(3);
    sum = tu / mau;
    if (a == 1) {
      c2.setText(sum + "");
    } else {
      c2.setText((sum + 2) + "");
    }
    if (a == 0) {
      c1.setText(sum + "");
    } else {
      c1.setText((sum + 5) + "");
    }
    if (a == 2) {
      c3.setText(sum + "");
    } else {
      c3.setText((sum + 4) + "");
    }
    c2.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 1) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }

    });
    c1.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 0) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    c3.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 2) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(Level4Activity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }
}

File Level5Activity.java:

package v1study.com.luyentoan;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class Level5Activity extends AppCompatActivity {
  TextView s1, s2, score;
  Button c1, c2, c3, back;
  int score1;
  int a;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level5);
    getViews();
    score1 = 0;
    develop();
  }

  void getViews() {
    s1 = findViewById(R.id.s1);
    s2 = findViewById(R.id.s2);
    c1 = findViewById(R.id.c1);
    c2 = findViewById(R.id.c2);
    c3 = findViewById(R.id.c3);
    score = findViewById(R.id.score);
    back = findViewById(R.id.back);
  }

  void addScore() {
    score1++;
    score.setText(score1 + "");
  }

  void deScore() {
    if (score1 > 0) {
      score1--;
    }
    score.setText(score1 + "");
  }

  void develop() {
    final Random random = new Random();
    s1.setText(random.nextInt(500) + "");
    s2.setText(random.nextInt(500) + "");
    a = random.nextInt(3);
    final int sum = (Integer.parseInt(s1.getText().toString()) + Integer.parseInt(s2.getText().toString()));
    if (a == 1) {
      c2.setText(sum + "");
    } else {
      c2.setText((sum + 2) + "");
    }
    if (a == 0) {
      c1.setText(sum + "");
    } else {
      c1.setText((sum + 5) + "");
    }
    if (a == 2) {
      c3.setText(sum + "");
    } else {
      c3.setText((sum + 4) + "");
    }
    c2.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 1) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }

    });
    c1.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 0) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    c3.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 2) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(Level5Activity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }
}

File Level6Activity.java:

package v1study.com.luyentoan;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class Level6Activity extends AppCompatActivity {
  TextView s1, s2, score;
  Button c1, c2, c3, back;
  int score1;
  int a;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level6);
    getViews();
    score1 = 0;
    develop();
  }

  void getViews() {
    s1 = findViewById(R.id.s1);
    s2 = findViewById(R.id.s2);
    c1 = findViewById(R.id.c1);
    c2 = findViewById(R.id.c2);
    c3 = findViewById(R.id.c3);
    score = findViewById(R.id.score);
    back = findViewById(R.id.back);
  }

  void addScore() {
    score1++;
    score.setText(score1 + "");
  }

  void deScore() {
    if (score1 > 0) {
      score1--;
    }
    score.setText(score1 + "");
  }

  void develop() {
    final Random random = new Random();
    s1.setText(random.nextInt(500) + "");
    s2.setText(random.nextInt(500) + "");
    a = random.nextInt(3);
    final int sum = (Integer.parseInt(s1.getText().toString()) - Integer.parseInt(s2.getText().toString()));
    if (a == 1) {
      c2.setText(sum + "");
    } else {
      c2.setText((sum + 2) + "");
    }
    if (a == 0) {
      c1.setText(sum + "");
    } else {
      c1.setText((sum + 5) + "");
    }
    if (a == 2) {
      c3.setText(sum + "");
    } else {
      c3.setText((sum + 4) + "");
    }
    c2.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 1) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }

    });
    c1.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 0) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    c3.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 2) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(Level6Activity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }
}

File Level7Activity.java:

package v1study.com.luyentoan;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class Level7Activity extends AppCompatActivity {
  TextView s1, s2, score;
  Button c1, c2, c3, back;
  int score1;
  int a, tu, mau, sum;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level7);
    getViews();
    score1 = 0;
    develop();
  }

  void getViews() {
    s1 = findViewById(R.id.s1);
    s2 = findViewById(R.id.s2);
    c1 = findViewById(R.id.c1);
    c2 = findViewById(R.id.c2);
    c3 = findViewById(R.id.c3);
    score = findViewById(R.id.score);
    back = findViewById(R.id.back);
  }

  void addScore() {
    score1++;
    score.setText(score1 + "");
  }

  void deScore() {
    if (score1 > 0) {
      score1--;
    }
    score.setText(score1 + "");
  }

  void develop() {
    final Random random = new Random();
    mau = random.nextInt(50);
    s2.setText(mau + "");
    tu = mau * random.nextInt(50);
    s1.setText(tu + "");
    a = random.nextInt(3);
    sum = tu / mau;
    if (a == 1) {
      c2.setText(sum + "");
    } else {
      c2.setText((sum + 2) + "");
    }
    if (a == 0) {
      c1.setText(sum + "");
    } else {
      c1.setText((sum + 5) + "");
    }
    if (a == 2) {
      c3.setText(sum + "");
    } else {
      c3.setText((sum + 4) + "");
    }
    c2.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 1) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }

    });
    c1.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 0) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    c3.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (a == 2) {
          addScore();
        } else {
          deScore();
        }
        develop();
      }
    });
    back.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Intent intent = new Intent(Level7Activity.this, StartActivity.class);
        startActivity(intent);
      }
    });
  }
}