Abacus History

Chinese Abacus History

The Suan Pan is an abacus of Chinese origin first described in a 190 CE book of the Eastern Han Dynasty , namely Supplementary Notes on the Art of Figures written by Xu Yue. However, the exact design of this suanpan is not known. Usually, a suanpan is about 20 cm (8 in) tall and it comes in various widths depending on the application. It usually has more than seven rods.

In china, the Chinese abacus came into common use during the Ming Dynasty. A book written by Wu Ching – Hsin – Min in 1450 gives description of the Abacus. The Chinese abacus used to have two counters above the bar and five below. This type of Abacus is still being used in china this day’s.

The abacus as we know it today, appeared (was chronicled) circa 1200 A.D. in China;in Chinese, it is called suan-pan . On each rod, this classic Chinese abacus has 2 beads on the upper deck and 5 on the lower deck; such an abacus is also referred to as a 2/5 abacus. The 2/5 style survived unchanged until about 1850 at which time the 1/5 (one bead on the top deck and five beads on the bottom deck) abacus appeared.

This configuration is used for both decimal and hexadecimal computation. The beads are usually rounded and made of a hardwood . The beads are counted by moving them up or down towards the beam. The suanpan can be reset to the starting position instantly by a quick jerk around the horizontal axis to spin all the beads away from the horizontal beam at the center.

Suan-pan can be used for functions other than counting. Unlike the simple counting board used in elementary schools, very efficient suanpan techniques have been developed to do multiplication , division , addition , subtraction , square root and cube root operations at high speed.

The modern suanpan has 4+1 beads, colored beads to indicate position and a clear-all button. When the clear-all button is pressed, two mechanical levers push the top row beads to the top position and the bottom row beads to the bottom position, thus clearing all numbers to zero. This replaces clearing the beads by hand, or quickly rotating the suanpan around its horizontal center line to clear the beads by centrifugal force

Circa 1600 A.D., use and evolution of the Chinese 1/5 abacus was begun by the Japanese via Korea. In Japanese, the abacus is called soroban . The 1/4 abacus, a style preferred and still manufactured in Japan today, appeared circa 1930. The 1/5 models are rare today and 2/5 models are rare outside of China(excepting Chinese communities in North America and elsewhere).

It is thought that early Christians brought the abacus to the East (note that both the suan-pan and the Roman hand-abacus have a vertical orientation). Aspects of Roman culture could have been introduced to China as early as 166A.D, during the Han Dynasty, as Roman emperor Antoninus Pius' embassies to China spread along the Silk Road.

There have been recent suggestions of a Meso American (the Aztec civilization that existed in present day Mexico) abacus called the Nepo hualtzitzin , circa 900-1000 A.D., where the counters were made from kernels of maize threaded through strings mounted on a wooden frame. There is also debate about the Incan Khipu — wasit a three-dimensional binary calculator or a form of writing? (q.v. Talking Knots of the Incas ).