Funbrain has a Math Arcade!
Math Builders (link)
Count Us In Games (link)
A site to help children understand basic numbers.
Math-a-rama 2nd grade (link)
Soft Schools Math Games - 2nd Grade (link)
National Library of Virtual Manipulatives (link)
The National Library of Virtual Manipulatives (NLVM) is an NSF supported project that began in 1999 to develop a library of uniquely interactive, web-based virtual manipulatives or concept tutorials, mostly in the form of Java applets, for mathematics instruction (K-12 emphasis).
Pattern Blocks (link)
Exploring Fractions with Shapes
Pizza Pizzazz (link)
Addition/Subtraction game (link)
Add and Subtract practice
Greater than or Less than (link)
Number Sequence (link)
Place Value (link)
Tangram Game (link)
Intermediate math concept game using tangrams. Online interactive
Place Value Pirates (link)
Read the place value clue at the top of the screen. Find the corresponding pirate who is standing on the platform that contains a number with a three in the tens column. Click on that pirate to destroy him.
Spin a Number (link)
Race against the computer to win this simple number game
Train Game (link)
Build you train using simple addition and subtraction
Cool Math (link)
A Maths Dictionary for Kids (link)
Math reference of terms sorted by letter.