The soroban is an abacus developed in Japan (generally known as the Japanese abacus). It is derived from the suanpan, imported from China to Japan around 1600. The soroban consists of an odd number of columns or rods, each with beads: one bead with a value of 5 (referred to as heaven beads) and 4 beads each with a value of 1 (referred to as land accounts). Each set of counts on each bar is divided by a bar often called a calculation bar. The number and size of beads on each rod make a standard size thirteen rod soroban much less cumbersome than a typical abacus.

The number of rods in a soroban is always odd and never less than nine. Basic models normally have 13 bars, however the number of bars common models will often increase to 21, 23, 27 and even 31, allowing additional numbers to be calculated. Each bar represents a digit, and a greater number of bars allows the representation of more numbers.

Beads and rods are made from a wide range of different materials. Most soroban made in Japan are made of wood and have wooden, metal, rattan, or bamboo rods for the beads to slide on. The beads themselves are normally biconal (shaped like a double cone). They are usually made of wood, although the beads of some soroban, particularly those made outside of Japan, can be made of marble, stone, and even plastic. The price of a soroban can increase depending on the materials.

In this computer age, however, the soroban is still thought to be useful as an educational and calculating device because it encourages concentration and patience. Many Japanese children go to private schools to learn how to use soroban. On November 12, 1946, a contest was held in Tokyo between the Japanese soroban, used by Kiyoshi Matsuzaki, and an electric calculator, operated by American military man Thomas Nathan Wood. The bases for scoring within the contest were the speed and precision of the results in the 4 fundamental arithmetic operations and a problem that mixes the four. The soroban won four to 1, with the electric calculator winning the multiplication.

In 1944, the Japan Chamber of Commerce and Industry launched the official soroban exam system, which is divided into 4 sections: multiplication, division, addition/subtraction, and denpyozan. An exam level is known as ‘kyu’. A person becomes a certified soroban instructor by passing the first (highest) kyu exam. Since the first official exam was administered, approximately 45 million people have taken it and about eleven million examinees have passed the third, second, and first kyu.

In the United States, the use of soroban had grown tremendously with new schools such as The Soroban School in New York. Parents have seen their children’s math and confidence improve with this age-old tool, not to mention their math grades. Finding sorobans can be difficult, so I recommend searching eBay for a few models. In my next article I will tell you how to choose the right soroban.