Collections

All NRICH games

Several excellent games from Manga High.

Ray Ray – Math is Fun

Math is fun – numerous games on their games pages.
Games2 includes a Parking lot game – similar to Rush Hour.
This page also has Tangrams.

Try RayRay!

Math Playground

Count On games collection

I Love Maths Games (E Hughes)

Math-Play – a large collection including Jeopardy Games

From Oswego City School District comes this collection – which includes games for younger students. These games are very good for mental arithmetic practice. Also note the Power Lines game.

Sheppard Software 

Math Games from Jefferson Lab (Thomas Jefferson National Accelerator Facility – Office of Science Education).