Take mental multiplication to an even higher level. Professor Benjamin shows you five methods for accurately multiplying any two-digit numbers. Among these: the squaring method (when both numbers are equal), the close together method (when both numbers are near each other), and the subtraction method (when one number ends in 6, 7, 8, or 9).
If you are a student or a professor:Watch now
If you are a librarian or a professor: