Virtual Math Manipulatives? Good...bad...What are they? Many web sites make them available to teachers (sometimes for sale).....but rather than refer you to a particular web site, I prefer to recognize one site because it provides an extensive list of web resources that offer virtual math manipulatives.
Part of a more comprehensive web site for the Computing Technology 4 Math Excellence, this "sub-page" offers resources that enable students to explore mathematics online.
Start by reading their short essay on virtual manipulatives, which provides a definition of a virtual manipulative, discusses the the role of virtual manipulatives in the math classroom, and states some cautions about using and overusing manipulatives (virtual or not).
After this background information, feel free to explore any of the many web resources for virtual manipulatives on the Web. The standard Illuminations from the National Council of Teachers of Mathematics is there with its many Java applets, but many of the others contain some useful ideas not seen before (at least by myself).
Now that your exploration is done, it is time for a quiz on what you learned.....Or, you can explore the other features on the CT4ME site.