activity_main.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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/txtValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="43dp"
        android:text="0"
        android:textSize="40sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/btnAdd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:text="add"
        app:layout_constraintBottom_toBottomOf="@+id/btnTake"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/btnTake" />

    <Button
        android:id="@+id/btnTake"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="84dp"
        android:text="take"
        app:layout_constraintBottom_toTopOf="@+id/btnShrink"
        app:layout_constraintEnd_toEndOf="parent" />

    <Button
        android:id="@+id/btnGrow"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:text="grow"
        app:layout_constraintBottom_toBottomOf="@+id/btnShrink"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/btnShrink" />

    <Button
        android:id="@+id/btnHide"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:text="hide"
        app:layout_constraintBottom_toBottomOf="@+id/btnReset"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@+id/btnReset" />

    <Button
        android:id="@+id/btnShrink"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="17dp"
        android:layout_marginBottom="203dp"
        android:text="shrink"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <Button
        android:id="@+id/btnReset"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="17dp"
        android:layout_marginBottom="69dp"
        android:text="reset"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>