A digital chalkboard would be an awesome tool for any math classroom. The Geometer's Sketchpad looks to give you a platform to create mathematical shapes and figures, but you'll have to pay up to use it. The price is probably too restrictive for home use, but could make it a great tool for classroom use.
The program costs $69.95 to unlock anything more than a 20-minute session that won't save or print your work. This price supports up to four computers. You can only access the drawing features of the program and not the measurement features if you don't pay, as well. The Geometer's Sketchpad offers five different tools to create geometric shapes to help you visualize math problems. Then, you can measure the angles and midpoints of the shapes to solve or create equations. There are dozens of different graph types supported by the program, complete with customizable coordinates and axes. There is a freehand tool, but drawing shapes is as simple as clicking where the points and midsections of the shape should be.
There are hundreds of different applications for the program. However, by making the price a little restrictive for anyone but educators, The Geometer's Sketchpad makes it so the program only works in a classroom. Students who want a similar experience have to pony up cash or try to make the program's limited free features work. If you have the money, it can be an incredibly valuable study aid though.
Editors' note: This is a review of the trial version of The Geometer's Sketchpad 5.05.