The Abacus 算盘

    The abacus, also called a counting frame, is a calculating tool that was in use centuries before the adoption of the modern numeral written system. 

While the first documentation of a Chinese abacus has been dated around the 14th century, some forms of the abacus or counting rods have appeared in history as early as 2700 BC in ancient Samaria (Sumar,苏美尔). Mentioned in ancient Roman texts, as well as among Egyptian hieroglyphics①(象形文字), one example of archaeological evidence of the Roman abacus dates to the first century AD and Greek artifacts dated as early as 500 BC. The abacus has survived the centuries with its purpose intact. Most often constructed of a wood frame with beads sliding on wire or wooden pegs, it is still widely used by merchants, traders and clerks in Asia, Africa, and elsewhere.

The Chinese abacus was created by a famous mathematician Cheng Dawei② of the Ming Dynasty, known worldwide as “the great master of zhu suan”. In Japan, he is worshipped as “the God of Arithmetic”, and August 8th was established as the “abacus festival” in commemoration of him.  

Known as the fifth great Invention of ancient China, the abacus can perform addition, subtraction, division, and multiplication; it can also be used to take square roots and cubic roots. 

The Chinese abacus divides the frame with a horizontal bar. The area above the horizontal bar, heaven, contains two beads per vertical rod; each has a value of five. In the lower area or earth, each vertical rod contains five beads, each with a value of one. Each vertical rod represents a unit of ten. Calculating is accomplished by moving beads toward or away from the horizontal divider. In the mid-1800s, the 2/5 abacus was replaced by the 1/5 abacus, and, by the 1930s, the most widely used form of abacus was the Japanese-made soroban(日式算盘), or 1/4 abacus.

The abacus remains a teaching tool in China and elsewhere in Asia. It is provided to school children as a method of simple calculation. Blind students, in particular, find the abacus to be a useful and more easily managed way to perform mathematics. Merchants and vendors in many locations throughout Asia also use the abacus to perform day-to-day sales and purchase calculations quickly and efficiently. Its cheap construction from everyday materials and manual operation makes it ideal for rural areas where batteries and electronics may not be readily available.    

Abridged and revised from

http://www.chinaculture.org/gb/en_chinaway/2004-03/31/content_46515.htm

Notes:

① Egyptian hieroglyphics：象形文字，距今5000多年前于古埃及出现，后来被欧洲人称作 “神的文字”。古埃及人认为他们的文字是月神、计算与学问之神图特造的，和中国人“仓颉造字”的传说很相似。

② Cheng Dawei: 程大伟，中国明朝珠算大师，珠算鼻祖，著有《算法统宗》。