This Android program defines a MainActivity class that extends Activity. The program imports necessary Android classes and defines methods for setting the content view on create, inflating the menu, and summing two numbers entered in EditText fields to display the result in a TextView. When the sum button is clicked, it gets the values from the EditText fields, parses them to doubles, calculates the sum, and sets the TextView to display the calculation.

1. PROGRAMA 2
Package com.example.programa2;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.TextView;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void sumar(View view){
EditText et1=(EditText) findViewById (R.id.num1);
EditText et2=(EditText) findViewById (R.id.num2);
TextView sol=(TextView) findViewById (R.id.res);

2. double n1=Double.parseDouble(et1.getText().toString());
double n2=Double.parseDouble(et2.getText().toString());
double r;
r=n1+n2
sol.setText(String.valueOf("El resultado de"+n1+"+"+n2+" = "+r));
}
}