The short cuts in the book don't require special math ability, just regular arithmetic. This is an interesting Web site with a wide range of topics and a daily e-mail for several subjects. There are several math tricks and games. This interactive online application basically imitates the BasketMath application. The Course Material pages house materials for educational use.
Site includes vast geometry resources and references.
Gallery of Interactive Geometry Part of the Geometry Center site above, the gallery contains several geometric figures, patterns, symmetry groups, etc., that can be played with like a game. They're everywhere, those bright, weird, beautiful shapes called fractals. Fractals are geometric figures, just like rectangles, circles and squares, but fractals have special properties that those figures do not have. Geometry Forum A K-12 Geometry site with several links including classroom materials for teachers and students, software for Geometry, Internet projects, and much more. The Pavilion of Polyhedreality This page includes several examples of polyhedral figures made from everyday items.