Have fun playing these games and exercising your brain.
http://www.mathsisfun.com/games/math-match-game.html
http://www.sheppardsoftware.com/braingames/boxes/boxes.htm
http://www.sheppardsoftware.com/braingames/memory2/memory2.htm
http://www.sheppardsoftware.com/braingames/memory3/memory3.htm
http://www.transum.org/software/SW/Starter_of_the_day/starter_October22.asp