The CRC Concise Encyclopedia of Mathematics is a compendium of mathematical definitions, formulas, figures, tabulations, and references. A collection of puzzles with printable worksheets and solutions for Grades K-8. Updated every month. Brain Teasers Teasers for students in Grades 4-8 organized by grade level.
Teachers can create or use ready-made online quizzes.
Fundrum My Conundrum Riddles, puzzles, and conundrums for Grades 4-12. The Geometry Center Course materials featuring a variety of interactive geometry projects and a gallery of geometry explorations. Math Collection of math sites for general math, algebra and geometry with puzzles and problems. Over 100 of interactive activities and puzzles that illustrate geometry concepts for students and teachers. Cyber School Resources Provides a Worksheet Maker that generates practice worksheets for Grades 2-6.