HotMath.org
© 2002 Hotmath Inc.
Formerly subscription-based HotMath.com, this new entity is free, and kids can use it 24/7. They go to the site, look up their textbook, turn to the right page and problem and then receive a step by step tutrial on how to solve it. Thirty US textbbooks from algebra through calculus are covered, and only odd-numbered problems are presented with solutions to keep students from cheating their way through class. This is a very valuable service; currently it is free. The company is vying for corporate sponsors to keep it that way. For more details, visit www.hotmath.org.
Internet Site
Teaches: math, algebra, geometry, calculus