"These Probability Simulations programs have been designed in order to allow teachers and students to simulate probability experiments over a long period of trials. " Y 5 and Y6 of MEP program.
"ATM speaks for creativity, thought, and the enjoyment of the struggle in calculation, reasoning and discovery"
Huge collection of resources for sale, includes software.
The Logo Workshop is designed to teach kids the basics of computer programming through a series of hands-on activities using a language called Logo.
An ambitious, but useful starting point.
"Magic squares received their name because there are so many relationships between the sums of the numbers filling the squares. "
Comprehensive site for Magic Squares