Abacus 101: beginner's abacus & mental math: learn the story, concepts & basics of traditional abacus (PENGUIN RANDOM HOUSE SOUTH AFR)

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 of abacus, how to read an abacus, and how to use an abacus to do simple calculation. The book i