virtual abacus to train in soroban program of mental calculation
the application "abacus" is in the form of a Japanese abacus named "soroban".
In this exercise you will train yourself to:
-Read the beads represent on the abacus
- Compose on the abacus the number
- Train for the four operations (addition-subtraction-multiplication and division)
the purpose of the "abacus" application is to improve the imaginition of pearls and the development of mental calculation skills.