How to express it with abacus?

Half a catty of eighty-two dual-purpose abacus is expressed as upper two and lower five beads.

Abacus is an auxiliary tool for manual operation and calculation. It originated in China and was an important invention in ancient China. Before Arabic numerals appeared, abacus was a widely used computing tool in the world. Now, abacus continues to be used in parts of Asia and the Middle East, especially in shops, which can be bought from shops that supply goods from China and Japan.

brief introduction

Although we have entered the era of electronic computers, when we look at China's ancient abacus, we have to admire the great wisdom of our ancestors. Generally, abacus is mostly made of wood (or plastic products). Arranging a string of equal number of beads in a rectangular wooden frame is called the first gear. One beam divides the beads into upper and lower parts, with each bead in the upper part representing 5 and each bead in the lower part representing 1.

Abacus shape

The new shape of the abacus is rectangular, with a wooden frame around it and a straight column inside, commonly known as "file". Generally, from the ninth gear to the fifteenth gear, the beam is placed horizontally on the gear, two beads are placed on the beam, each bead counts as five, and five beads are placed under the beam, each bead counts as one. Calculate the beads after positioning, and you can do algorithms such as addition, subtraction, multiplication and division.

Main types

It is worth noting that the word abacus does not refer specifically to China's abacus. Judging from the existing literature, many ancient civilizations had their own calculation tools similar to abacus. All kinds of abacus can be roughly divided into three categories: sand table type, calculation board type and bead-piercing abacus type.

The origin of development

Abacus is a traditional calculation tool in China, which evolved from the calculation widely used as early as the Spring and Autumn Period. It is not only an important invention in ancient China, but also a widely used computing tool before Arabic numerals appeared.

value

Because the abacus is simple to make, cheap, easy to remember and calculate, it is widely used in China and spread to Japan, North Korea, the United States and Southeast Asia. Now it has entered the era of electronic computers, but the ancient abacus still plays a certain role.