I have difficulty setting up the classes and would like an example, with class screen 1, class screen2, class calculation accessed by both.
Another doubt is always going to have the initial body
public class Tela1 extends Activity {
@Override
public void onCreate(Bundle savedInstance) {
super.onCreate(savedInstance);
I think I understand what you need. You want to know how to create two activities (screens) and have a class named Calculo to access them. But your question is HOW create two activities and have an intermediate class to do the calculations. Here in the forum you do not have any new learning courses in these tools. However, if in the middle of an Android course you have problems, you ask a question here by posting the code that we can help in problems, as in other questions.