Sum Fun - A fun number puzzle game for iPhone and iPad.
Yasminoku - Sudoku game and solver totally written in DHTML.
NumberDrop - A uniquely challenging math puzzle game.
HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
dworksheets.com - Free K-12 math worksheets to assist students, teachers, parents & tutors to practice, teach or prepare grade school assignments, classwork or homework questions & answers is available online in printable & downloadable format.
nsudoku - A Sudoku game made with ncurses.