The following links have fun games to practice your math skills. The best part is that they are free!
funbrain.com - Math games for elementary and middle schoolers
mathplayground.com - Online Games, Word Problems, Puzzles
math-play.com - Online games to practice basic math up to Algebra
coolmath.com - Math Lessons, Games, Worksheets, and Puzzles
coolmath4kids.com - Math Lessons, Games, Worksheets, and Puzzles
math.com - Homework Help, Worksheets, Puzzles, Games and Lessons
mrnussbaum.com - Interactive games, activities, and worksheets.
aplusmath.com - Games, Flashcards and Homework Help
kidsnumbers.com - Math Practice, Worksheets, and Games
mathcats.com - Math Projects, Games, Trivia, Practice
hoodamath.com - Free online math games (really fun!) to practice basic skills
mathnook.com - Free online math games to practice the basics
kenken.com - Free online puzzles
thinkfinity.org - Free interactive math games
softschools.com - Free middle school math games
multiplication.com - Online games to learn times tables