Cynthia Lanius is director of the centre for excellence and equity in education at Rice University, Houston, Texas, USA. The earlier site she produced for fractals is superb. This one uses the Internet to put across some basic ideas about maths including cartography, fractals, infinite series, pattern blocks, graphs and duelling pinwheels. Suitable for 7 to 14-year-olds.
http:math.rice.edu%7ElaniusLessons