what is abacus system
Part of the Peripherals glossary: An abacus is a manual aid to calculating that consists of beads or disks that can be moved up and down on a series of sticks or strings within a usually wooden frame. The abacus itself doesn't calculate; it's simply a device for helping a human being to calculate by remembering what has been counted. The modern Chinese abacus, which is still widely used in China and other countries, dates from about 1200 A.D.