An excellent, free online graphing calculator. All you need is a valid email address to create an account.
Another excellent, free online tool for working with geometry and algebra concepts. No account needed. Just save your project to your computer's hard drive.
A free, creative presentation tool. All you need is a valid email address to create an account.
Tower of Hanoi
A digital version of the ancient disc and peg game. How many discs can you move?