Multiplication Express for Mac

From Vertical Eye:

Multiplication Express is a game that takes a radically different approach to reinforcing multiplication skills.

The game presents the player with a blank multiplication table and an answer piece, the player must place the answer piece in its correct position. After a piece has been placed a new answer piece appears and the process is repeated until the multiplication table is filled in.

Multiplication Express is not only fun, it's addictive. It's a truly original game, not simply math tacked onto an existing game.