To generate a question, press "New Question" and a window with a question, a blank cell and a "Check Answer" button will appear.
Determine the value of the answer(remember the dimension restrictions), enter it on the cell and press the "Check Answer" button. Results appear in the table on the main page.
If the small window covers up any part of the main window, you may drag it to a new location.
If you miss a problem three times, pressing "Show Answer" will cause the correct answer to appear.