GCompris - Educational Game for Children 2 to 10 years old.
MathIsFun Times Table - Learn Your Multiplication Tables
Tux Paint - Tux Paint is a free, award-winning drawing program for children ages 3 to 12 (for example, preschool and K-6).
I Know It - "I Know It" is an online game for practicing primary-level math concepts.
TuxMath (Tux of Math Command) - Tux, of Math Command, AKA TuxMath, lets kids hone their arithmetic skills while they defend...
Akribian - Akribian turns children into Mathemagicians with their new iOS app, Count on me!