Minimially, your calculator should have +, -, *, /, C (clear), and =. It should display a running total and should select the input TextField after each operation so that the user can simply type the next number without having to use the mouse (as demonstrated in class).
Make it work like a real calculator. So, starting with 0, if the user types 4, then +, then 6, then =, it should say 10. If they then type -, then 3, then +, it should say 7, and when they then type 10 and =, 17.
Decide if you are going to embed or link your calculator;either way is fine.