Updated November 28, 2007
Multiplication Drill (0 through 12)
Updated February 3, 2006
Sudoku Solver Java Applet
Updated January 3, 2006
Simple Continued Fractionator Java Applet
For Conway's Angel Problem, please see the entry on Wikipedia.
September 15, 2005
Unusual Proof of Irrationality of The Square Root of 2