Counting in your head is difficult, especially when you have to deal with large numbers. Therefore, since ancient times, man has sought to facilitate this process with the help of various devices. One of these devices is the abacus - the predecessor of the accounts, adding machine and calculator.
The abacom is the simplest device for arithmetic calculations, invented about five thousand years ago and used until the 18th century. The word itself is of Greek origin and means "counting board" in translation. The abacus was used by the ancient Greeks, Egyptians, Romans, Chinese, Japanese.
The abacus looked like a board (not necessarily wooden, it was often made of clay) with indentations or lines carved into it. The counting stones were moved along these depressions (lines). Moreover, in Ancient Egypt it was customary to move pebbles from right to left, and in Greece, on the contrary, from left to right. In Egypt, the abacus was later improved and began to resemble abacus: pebbles were strung on a wire fixed in a wooden frame.
The abacus used a five-fold number system; abacus was transferred to the decimal system only in the 2nd millennium AD. The abacus were used not so much for calculations as for storing intermediate results. However, on the abacus it was possible to perform all four arithmetic operations and even extract the square and cube roots from the number.
The Chinese version of the abacus (Xuanpan), as well as the Japanese version (Soropan), also outwardly resembled abacus: wires were enclosed in a bamboo frame with special counting bones, carved from wood, strung on them.
Abacus was invented in the late 16th or early 17th century. Their main difference from the abacus was the use of a decimal number system, as well as an increase in the digit capacity of each row of numbers. On accounts it was possible to calculate even fractions - tenths and hundredths of a number. The accounts have not undergone any modifications since their inception. They were widely used to teach arithmetic to schoolchildren. But calculators appeared, immeasurably facilitating the process of arithmetic calculations, and abacus practically disappeared from everyday life.
However, calculators that instantly produce a ready-made result do not at all contribute to an increase in the level of mathematical skills in children. Therefore, in Japan, in recent years, abacus abacus training has been reintroduced in many schools: the practical and forward-thinking Japanese are interested in developing math skills in children as early and better as possible.
