add two

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

public class MainActivity extends AppCompatActivity {

private EditText editTextNumber1;
private EditText editTextNumber2;
private Button buttonAdd;
private TextView textViewResult;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    editTextNumber1 = findViewById(R.id.editTextNumber1);
    editTextNumber2 = findViewById(R.id.editTextNumber2);
    buttonAdd = findViewById(R.id.buttonAdd);
    textViewResult = findViewById(R.id.textViewResult);

    buttonAdd.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            calculateAddition();
        }
    });
}

private void calculateAddition() {
    double number1 = Double.parseDouble(editTextNumber1.getText().toString());
    double number2 = Double.parseDouble(editTextNumber2.getText().toString());

    double result = number1 + number2;

    textViewResult.setText("Result: " + result);
}

}

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:gravity="center" android:padding="16dp" tools:context=".MainActivity">

<EditText
    android:id="@+id/editTextNumber1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="numberDecimal"
    android:hint="Enter Number 1"/>

<EditText
    android:id="@+id/editTextNumber2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="numberDecimal"
    android:hint="Enter Number 2"/>

<Button
    android:id="@+id/buttonAdd"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Add"
    android:layout_marginTop="16dp"/>

<TextView
    android:id="@+id/textViewResult"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="24sp"
    android:textStyle="bold"
    android:layout_marginTop="16dp"/>

</LinearLayout>