http://prongo.com/games/ages9-12.html
Puzzles and math games for students aged 9-12.

http://www.mathcats.com

Learn Math from a few really smart cats.

http://www.aplusmath.com

Improve you Math skills with puzzles, flash cards, worksheets, and other Homework Helpers.

http://www.mathsisfun.com

Math is definitely fun!

http://www.kidsnumbers.com

Learn Math step by step with this exciting site just for you!

http://www.coolmath4kids.com

This cool Math portal is jam packed with brain benders, games, puzzles, flashcards, and more.

http://www.webmath.com/

Solve all your Math problems here.

http://www.mathway.com/

This site is designed for older students to excel at Math. You might need this tomorrow.

http://users.altec.org/~scherrer/games/matrix/penguin/1020/intros2/3/penguin10_20c.htm
Guide Plotter the Penguin from point to point by determining the slope