Math Resources:
Cool Math Games: games, tools and activities on topics like algebra, pre-calculus and more
Desmos: online graphing, scientific, four function calculators and more
GeoGebra: math resources for algebra, geometry, number sense, measurement, operations, statistics and probability to learn about and practice
Get in the Math: combines video and web interactivity to develop algebraic thinking skills and solving real-world problems
Khan Academy: access videos and practice pages
Paul's Online Notes: While this site is designed to supplement a college professor's math course, he provides some helpful cheat sheet for alegbra, trignometry, and calculus as well as practice problems and the solutions
Wolfram Mathworld: a dictionary useful for mathematical explanations