ThinkMath is from Harcourt School Publishers. There are many reinforcement activities for grades K-5 that cover Number, Operations, Data Analysis, Geometry, Measurement, Time & Money, Probablility, and Algebra.

Blocks is an online building toy for kids of all ages. Create blocks and move them around by typing in commands from a simple programming language. Anyone can do it and there's nothing to install.

mathtrain_logo.gif MathTrain.TV is a free educational "kids teaching kids" project fromstudents at Lincoln Middle School in Santa Monica, CA. There are many math videos that you can use from upper elementary and up. There are videos created by both teachers and students. Make sure to view a video in advance of using it in your lessons. Here's an example on probability. If you would like to start a project like this with your students, let me know.

Web Sites for Practice

CoolMath4Kids - Coolmath has a ton of cool math games and puzzles, lots of really clear math lessons (arithmetic, fractions, decimals, algebra, etc.

Just for fun: Number Gossip - Enter a number and the gossip will tell you everything you wanted to know about it but were afraid to ask. Tip: Enter the numbers' digits not their words. For example, "2" will be recognized, but "two" will not.