Japanese Antique Wooden Abacus Soroban Calculator 23 Columns Digits Soroban  1945

This is a Soroban or an abacus and it is a type of calculator used in banks, businesses and at homes for over 450 years in Japan. Encased in a wooden frame and suspended with the metal rods, the top beads represent fives and bottom beads represent ones. Each column represents decimal point and beads are counted by sliding them on the rods.When one of the columns is set as the ones column, in this case 4th and 11th column from the left, the next adjacent to the left becomes the tens column, then hundreds, thousands, ten thousands and so on. The decimal fraction can be displayed on the right side of the ones column as well.In Japan, the art of using the abacus has been carefully cultivated. In 1928, the Japanese Chamber of Commerce and Industry established standardized abacus examinations and many millions of people had been participating to take the test to be certified. Although computers now carry out complex calculations, abacus is still used in offices, shops alongside computers and electronic calculators even today.The abacus is also a very useful tool in general mathematics education because of its concrete visible display of numbers by beads that enable students to grasp the concept of numbers, particularly in understanding place value. As a math tool, it has been continuously used by the blind and visually impaired in Japan since the first school for the blind was established late in the 19th century.This is an Itsutsudama type Soroban. The earlier prototype abacus consists of a rectangular wooden frame divided into two parts by a beam, with two rows of 5- beads in the upper deck instead of one bead like this particular piece and five 1-beads in the lower deck called the Mutsudama type Soroban. This is probably close to the original style when abacus came from China and this was because the Chinese unit of weight was base sixteen count, 15 numbers (two 5- beads plus five 1- beads) in each column were needed.This style was slightly modified in the early Meiji Period (1868-1912) and replaced by only one 5-bead in the upper deck, called the Itsutsudama Soroban like this particular piece. Most people had switched to this style from the older Chinese style by around 1880. In the 1930's, yet another modification was implemented by reducing the lower deck to just four 1-beads, called the Yotsudama Soroban. This was because one 5-bead and four 1-beads were considered sufficient to do all the calculations.When primary school textbooks were revised in 1935, the four-beaded Yotsudama Soroban became the standard. The entire casing, each bead of this piece and the rods holding the beads in place are made of wood. 

Japan
Main article: Soroban

Japanese soroban
In Japan, the abacus is called soroban (算盤, そろばん, lit. "counting tray"). It was imported from China in the 14th century.[31] It was probably in use by the working class a century or more before the ruling class adopted it, as the class structure obstructed such changes.[32] The 1:4 abacus, which removes the seldom-used second and fifth bead became popular in the 1940s.

Today's Japanese abacus is a 1:4 type, four-bead abacus, introduced from China in the Muromachi era. It adopts the form of the upper deck one bead and the bottom four beads. The top bead on the upper deck was equal to five and the bottom one is similar to the Chinese or Korean abacus, and the decimal number can be expressed, so the abacus is designed as a one:four device. The beads are always in the shape of a diamond. The quotient division is generally used instead of the division method; at the same time, in order to make the multiplication and division digits consistently use the division multiplication. Later, Japan had a 3:5 abacus called 天三算盤, which is now in the Ize Rongji collection of Shansi Village in Yamagata City. Japan also used a 2:5 type abacus.

The four-bead abacus spread, and became common around the world. Improvements to the Japanese abacus arose in various places. In China an aluminium frame plastic bead abacus was used. The file is next to the four beads, and pressing the "clearing" button put the upper bead in the upper position, and the lower bead in the lower position.

The abacus is still manufactured in Japan even with the proliferation, practicality, and affordability of pocket electronic calculators. The use of the soroban is still taught in Japanese primary schools as part of mathematics, primarily as an aid to faster mental calculation. Using visual imagery can complete a calculation as quickly as a physical instrument.[33]