Create a very basic calculator, map out the numeric keypad (17 buttons) and an EditText view

Create a very basic calculator, map out the numeric keypad (17 buttons) and an EditText view. If text is given, prompt the user with a message that complains about the error.
Toast.makeToast(getApplicationContext() , "error Message" , Toast.LENGTH_LONG).show();
The calculator should be able to allow the user to add and subtract. Remember that you want to receive input from the user and display the results.
For this activity, you will be submitting your entire project directory. If you right-click on your project directory you can send everything to the Compressed folder, which will create a zip file.