This is a simple guidebook for people who are interested in learning the introduction of how an Abacus works. The book includes simple explanation of the theory

This is a simple guidebook for people who are interested in learning the introduction of how an Abacus works. The book includes simple explanation of the theory

The abacus is as useful and effecient a machine today as it was when it was first created centures ago. Whether you're an expert in the latest computer technolo

Results from national and international assessments indicate that school children in the United States are not learning mathematics well enough. Many students c