Soroban

The Soroban (Japanese算盘or十 露 盘) is the Japanese abacus, which is usually served lying on the table with one hand. It consists of a frame and a plurality of rods on which there are balls. Large soroban contain about 20 of these rods. It is more flexible, but also more challenging to use than the typical European Schulabakus because it is divided by a rail in an upper (also called heaven ) and a lower part. In the upper part in each case is a ball which has a value of 5, the lower four or five, each of which has the value 1. The Soroban goes back to the Chinese Suanpan, but the upper part contains two balls to hexadecimal units to facilitate calculations (which were unusual in Japan).

While the Suanpan in China part of everyday life in the 14th century, the Soroban in Japan spread only since the 16th century. Mathematical geniuses as Mōri Shigeyoshi and arithmetic book authors such as Yoshida Mitsuyoshi made ​​him popular at the beginning of the Edo period. The Soroban remained until the 19th century an essential computational tool for school and work. Only the education reforms at the beginning of the Meiji period, which forced western computing techniques could oust him briefly. Since the 1920s, however, he experienced in the simplified form with 4 1 balls a renaissance. Skilled computer reached using the Soroban higher computing speed than the user of mechanical calculating machines. Only through affordable electronic calculator he lost again in importance, but he is still widely used today in Japan.