The site is from England, but there appear to be some great resources here for Math.

Huge array of educational games for chidlren. Geared mostly for grades K-5.

This is a great game and really makes you think! It would be wonderful for pairs of younger students to work on together or as a whiteboard, whole class activity.

Great fractions game!

Sites to use with Interactive Whiteboards Grades 6-12

The goal of this project is to provide teachers a list of common terms or phrases aimed at improving vocabulary development of students in Tennessee. Although there is no single best way to teach terms and phrases, Dr. Marzano's research and theory on vocabulary development does point to a few generalizations that provide strong guidance. This site is dedicated to the sixth step in that process by providing a collection of games and activities designed to review and strengthen vocabulary development.

A collection of interactive sites on the Web that estimate, calculate, evaluate translate

Movies and interactive tutorial link

Collection of modules that can be used in the studying or teaching of calculus

These pages present interactive Java applets for teaching and learning single variable calculus. They use graphs and tables to illustrate concepts in calculus and allow the user to dynamically change the functions involved or the point on the graph that is of interest. These pages can be explored by students learning calculus, or used by teachers while teaching calculus, and are geared to the topics covered in AB and BC Advanced Placement Calculus.

Flash-based games. Great for IWB

All subject areas.

Interactive whiteboard activities. Those for lower grade levels can be found at the bottom of the page.

Huge list of activities categorized by discipline and most are marked as IWB activities.