The fifth great invention of China - Abacus

abacus

Abacus, one of the important achievements of ancient Chinese invention and creation, has a history of more than 2000 years. China is the first country in the world to invent abacus. The abacus evolved from the ancient "calculation". "Calculation" is the use of "counters" - a kind of cutting bamboo sticks to carry out operations. In the late Tang Dynasty, the multiplication and division method of "calculation" began to be used. In the Song Dynasty, the division formula of "calculation" was produced. The name "abacus" was officially named in the book of ten complete algorithms by Wu Jing, a mathematician in the Ming Dynasty. Around the early Ming Dynasty, abacus gradually became popular, and there were many works on abacus in the mid-15th century. Because abacus formula is easy to remember and calculate, it is widely used in China. At the same time, it also spread to Japan, North Korea, India, the United States, Southeast Asia and other countries, and was widely welcomed.

abacus

The abacus is composed of a frame, a beam,  pigeonholes and calculation beads. The four sides of the abacus are called frames, and the bars in the middle of the abacus are called beams. In the abacus from the top through the beam to the bottom of the stick is called the pigeonholes , the abacus on the beads, called calculation beads. The new shape of the abacus is a rectangle, with a wooden frame around it and a wooden column inside, commonly known as "pigeonholes". Generally, from the ninth to the 15th gear, there are two beads on the beam and five beads on the beam. Each bead is counted as five, and five beads under the beam is counted as one. During the calculation, the beads are moved after positioning, and the addition, subtraction, multiplication and division can be done. The abacus is made of wood, copper, iron, jade, plastic and bone. The shape of abacus includes rectangle, fan, octagon, Ruyi, etc. The better quality wooden abacus is made of Huanghua pear, red sandalwood and sour branch wood. The wood beads are bright and the wood grain is clear. On December 4, 2013, China's abacus program was included in the UNESCO intangible cultural heritage list. Now, some schools in China have set up extra-curricular study groups to teach abacus mental arithmetic. According to experts' research, learning abacus mental arithmetic can improve children's mathematical calculation ability, enhance children's concentration, cultivate pictorial memory, learn to use hands and brain together, and develop good quality of realistic rules. In addition, in the international community of rehabilitation medicine for mentally retarded children, the use of abacus mental arithmetic is beneficial to the rehabilitation training of mentally retarded children, which has aroused people's attention. Nowadays, China's abacus has gone abroad and become the "emissary" of spreading Chinese culture, which is welcomed by many foreign friends. Some countries set up "abacus Festival", some are included in the primary school curriculum, and some carry out the national abacus tour demonstration performance.

The abacus, known as "the fifth great invention of China", has played an important role in the development of ancient Chinese culture. It has been used in everything from business accounting to astronomy and geography. Who was the inventor of the abacus? What is the exact year of invention? The word "abacus" is the first to be seen in Xu Yue's work "Shushu Jiyi" in the Eastern Han Dynasty. However, the note says it can only do addition and subtraction. Today, at most, this is a rudiment of abacus. According to the available reliable data, abacus was invented in song and Yuan Dynasties. People have consulted a large number of historical documents, but can not find the name of the inventor of abacus. This shows that the feudal rulers did not pay enough attention to scientific and technological inventions. On the other hand, it also shows that their inventions are a gradual process, which is gradually improved and perfected. It is difficult to say who is responsible for their inventions. Abacus is one of the important scientific achievements in ancient China. It has the advantages of simple structure, easy operation and easy to carry, so it has been widely used for a long time. Abacus has been widely used in China and spread to North Korea, Japan, Southeast Asia and Arabia. It has made an important contribution to world civilization.