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Saturday 4 June 2011

Abacus

An abacus is a tool that has been used since ancient times for performing arithmetic calculations. It consists essentially of a tablet or frame bearing parallel wires or grooves on which counters or beads are moved.

Use of the abacus, with its beads in a rack, was first documented in Han Dynasty China in about AD 190.

According to legend, the abacus was invented by a man named Li Sou working for the Yellow Emperor. Li used a big mud plate and white pearls, which were divided into 10 strings of 10 beads.

"Abacus" derives from the Hebrew ibeq, meaning to " wipe the dust" or from the Greek abax, meaning "board covered with dust", which describes the earlier calculating devices used by the Babylonians.

Photo Abacus 1680-1117 by Paul Schadler

The Chinese version was the speediest way to do sums for centuries and, in the right hands, can still outpace electronic calculators.

The abacus is still in regular use in eastern countries, and in China it is called a suanpan (computer tray).

The soroban is an abacus developed in Japan. It is derived from the ancient Chinese suanpan, imported to Japan in the 14th century.

In Japan, the latest versions of the abacus include a dual bead and digital calculator.

The standard size of a modern Japanese abacus is smaller than the Chinese one. The Japanese abacus has 1+4 beads per row, rather than 2+5 for the Chinese.

A suanpan (top) and a soroban (bottom). 

There are classes in Japan that teach kids how to use the Soroban abacus to develop faster skills in arithmetic. After a few years they no longer even need to use a real abacus to perform fast mental calculations since they can already visualize an image of it.

Source The Independent November 3, 2007

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