Number Squares is a math game which allows the use
of addition, subtraction, multiplication, and division problems.
You are allowed to change the type of problems used, and the range
of what the program can select for the answer on a screen. After
the game is started, the program selects an answer and generates
16 problems. You move around the board with the arrow keys and
press the space bar on a problem if you think it gives the answer
at the top of the screen. When all correct answers are found,
the computer start a new screen.
(taken from nrsq.doc)