Sig Fig Practice
Determining number of sig figs
sig fig quiz

Chemistry teacher support group, with activities, and other resources for chemistry teachers.
Full of chemical new, and resources for teachers, as well as the standards for teaching chemistry in the US
Useful tool for finding molecular weights, and structures, as well as IUPAC names, and CAS Numbers of compounds.
Official site of the Colorado Geologic Survey, all kinds of information on Coloraod geology.
National Science Teachers Association website.
Colorado education standards.
Journal of Chemical Education website.
The chemistry Hypermedia Project - A deep online resource of explanations, and concepts in chemistry.
The United States Geological Survey's education site. Full of fun activities and information relating to geology (Earth Science.)