Fun Brain http://www.funbrain.com/kidscenter.html
Gamequarium http://www.gamequarium.com/math.htm
A+ Math http://www.aplusmath.com/Games/index.html
Cool Math For Kids http://www.coolmath4kids.com/
Multiplication games http://www.multiplication.com/interactive_games.htm
Woodlands Jr http://www.woodlands-junior.kent.sch.uk/maths/
PBS Kids http://pbskids.org/cyberchase/games.html
Harcourt School http://www.harcourtschool.com/menus/auto/13/5.html
Online Manipulatives http://nlvm.usu.edu