A free comprehensive math resource site. Find free worksheets, math ebooks for elementary grades, extensive link list of games, interactive tutorials & quizzes, curriculum guide, and math teaching help articles/lessons. The resources emphasize understanding of concepts instead of mechanical memorization of rules.
StarLogo is a programmable modeling environment for exploring the behaviors of decentralized systems, such as bird flocks, traffic jams, and ant colonies. It is designed especially for use by students.