202 1 elementary school uses an abacus with several beads.

Expand:

Abacus is an auxiliary tool for manual operation and calculation. It originated in China and has a history of more than 2,600 years. This is 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. In the west, it is sometimes used to help children understand numbers. Some mathematicians like to experience the feeling of calculating simple arithmetic problems with an abacus. 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. From right to left, each bead represents a decimal number, ten, hundred, thousand and ten thousand. Coupled with the software-a set of operating formulas for finger-playing rules, it can solve all kinds of complicated operations and even prescribe multiple prescriptions. Abacus is the predecessor of modern computer and the symbol of ancient computing technology in China.