From Tadpole Interactive:
Math Attack incorporates basic rules of addition, subtraction, multiplication and division as a means of fending off waves of attacking biplanes as they attempt to demolish your building projects. Solve problems in progressively demanding intervals to blast aircraft with corresponding equations before they pummel your structures into oblivion as you accumulate statistics per each right and wrong answer obtained.
The demo version offers two of the original seven modes of play (addition and division) in conjunction with a 3 minute time limit imposed per each play session. The full version of the game alleviates these limitations.