Ask Eric (Math Lesson Plans) - Hundreds of unique lesson plans written and submitted to AskERIC by teachers from all over the United States.

Census - Using census data in the classroom. Activities, free materials, fact sheets, and more.

Educast - Hundreds of math lesson plans. Search on grade level or theme. Also, Internet-based lesson plans for web-connected classrooms.

Explorer - A collection of educational resources (instructional software, lab activities, lesson plans, student created materials ...) for K-12 mathematics and science education.

University of Illinois Office for Mathematics, Science and Technology Education (MSTE) - Offers a searchable mathematics lesson database, technology intensive lessons (TCD) , educational Java applets, and lessons for K-12 statistics. Teachers can also add a Lesson to the Mathematics Database.

Frank Potter's Science Gems - Mathematics. A huge collection of links to lesson plans, especially at the high school level.

GirlTECH Lesson Plans - GirlTECH teachers designed these lesson plans to take full advantage of Internet resources and to teach mathematics and science concepts in new and exciting ways.

K-5, 6-8, 9-12 Math Lessons - Teacher-created lesson plans from the Academy Curriculum Exchange. Part of an Ohio nonprofit corporation which has been established to be a central repository for information dealing with Free-Nets/Community Networks.

Lessons Integrating Technology - Intel ACE lesson plans submitted by teachers.

Math Forum Lesson Plans - Links to K-12 lesson plans.

Mega-Mathematics - lesson ideas on interesting subjects such as coloring and graphing games.

Teaching Ideas (Maths) - fun and easy ideas for elementary classrooms.