HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
Math Games - Math Games is a website which kids in Preschool through 8th grade can practice math.
Yasminoku - Sudoku game and solver totally written in DHTML.
DragonBox Algebra - DragonBox Algebra 5+ - The educational game that secretly teaches you algebra.
Simple Sudoku - Freeware Sudoku Puzzle Maker and Solver
GCompris - Educational Game for Children 2 to 10 years old.