Soroban Abacus History

Abacus The Soroban's physical resemblance to the Chinese suanpan clearly indicates its origin. The number of beads, however, is similar to the Roman Abacus, which had four beads below and one at the top.

Most historians of the Soroban agree that it has its roots on the suanpan's importation to Japan via the Korean peninsula in the 15th century. When the suanpan first became native to Japan as the Soroban (with its beads modified for ease of use), it had two heavenly beads and five earth beads. But the Soroban was not widely used until the 17th century, although it was in use by Japanese merchants since its introduction. Once the Soroban became popularly known, several Japanese mathematicians, including Seki Kowa, studied it extensively. These studies became evident on the improvements on the Soroban itself and the operations used on it.

In the construction of the Soroban itself, the number of beads had begun to decrease, especially at a time when the basis for Japanese currency was shifted from hexadecimal to decimal. In around 1850, one heavenly bead was removed from the suanpan configuration of two heavenly beads and five earth beads. This new Japanese configuration existed concurrently with the suanpan until the start of the Meiji era, after which the suanpan fell completely out of use. Later in 1930, one earth bead was further removed, forming the modern configuration of one heavenly bead and four earth beads. This configuration became popular in the 1940s.

Also, when the suanpan was imported to Japan, it came along with it its division table. The method using the table was called kyūkihō ("nine returning method") in Japanese, while the table itself was called the hassan ("eight calculation"). The division table used along with the suanpan was more popular because of the original hexadecimal configuration of Japanese currency. But because using the division table was complicated and it should be remembered along with the multiplication table, it soon fell out in 1935 (soon after the Soroban took its present form in 1930), with a so-called standard method replacing the use of the division table. This standard method of division, recommended today by the Japan Abacus Committee, was in fact an old method which used counting rods, first suggested by mathematician Momokawa Chubei in 1645, and therefore had to compete with the division table during the latter's heyday.

Abacus for the Visually Challenged

As a math tool, the Abacus has been used by the blind in Japan since its first school for the blind was established late in the nineteenth century. They were unable to use ordinary Abacus whose beads easily moved. So a special kind of Abacus for the blind was developed. In the US it is widely used at schools for the blind. In 1965, certified examinations for the visually challenged started.

Source : Wikipedia