android.widget.Button cannot be cast to android.widget.EditText

Question

Developing my first Android calculator application, I succeeded in updating a TextView in a new activity by passing the answer via an intent, but this requires the user to h

Answer 1

It seems like either R.id.number1 or R.id.number2 is a Button. Check your XML and make sure it's an EditText.

Edit: Original answer didn't work, but cleaning the project solved the problem.