The abacus system of mental calculation is a system where users mentally visualize an abacus to do calculations. No physical abacus is used; only the answers are written down. Calculations can be made at great speed in this way. For example, in the Flash Anzan event at the All Japan Soroban Championship, champion Takeo Sasano was able to add fifteen three-digit numbers in just 1.7 seconds.
This system is being propagated in China, Singapore, South Korea, Thailand, Malaysia, and Japan.
The standard abacus can be used to perform addition, subtraction, division, and multiplication; the abacus can also be used to extract square-roots and cubic roots.
- Mental abacus does away with words
- Sequential Neural Processes in Abacus Mental Addition: An EEG and fMRI Case Study