Creating an addition tutor with 2 randomly selected integers.

The form needs to contain one command button that should present a new addition problem and one should allow the user to quit.  There should be a text box to present the question and accept the answer and another to tell the user whether her answer was correct.  End program with the quit button.  After that is working, add option buttons to allow the user to choose easy medium or hard problems, i.e., numbers between 0 and 9, 0 and 99 or 0 and 999.

I am at the understanding that one variable, X is x-int(rnd*10). Then y=int(rnd*10). If this is correct what should the Command buttom that generates a new problem look like? I am having a tough time visualizing this.
Thx!