(Sample link) NASA for high school students http://www.nasa.gov/audience/forstudents/9-12/features/index.html
(Sample link) National Geographic http://www.nationalgeographic.com
Hotmath.com is a site available to all PVI math students. Students have access to explanations to the odd numbered problems in their textbook. Password: 1panther1. hotmath.com
Algebra.help.com offers lessons on basic algebra topics and techniques, study tips, calculators, interactive worksheets and more. http://www.algebrahelp.com/
CoolMath.com has hundreds of really easy to follow lessons and examples that will make you a successful algebra student. http://www.coolmath.com/
Math.com offers free homework help and reference materials. http://www.math.com/
NutshellMath.com http://NutshellMath.com/