Math Links Everyday Math
Interactive Math Games
Fun Brain
Time Games
Function Machine
http://pbskids.org/cyberchase/math-games/stop-creature/
http://www.amblesideprimary.com/ambleweb/mentalmaths/functionmachines.html
http://www.topmarks.co.uk/PlayPop.aspx?f=inversemachinev3
First in Math