The earliest tools used by human beings to count are fingers and toes, but they can only represent numbers within 20. When the number was large, primitive people mostly counted pebbles and beans. Gradually, people were not satisfied with counting by grains, so they invented the method of knotting to describe counting, and described counting on hides, bones, trees and stones. In ancient China, counting was done with sticks made of wood, bamboo or bones, which was called counting chip. These counting methods and symbols gradually became the earliest digital symbols (numbers). Today, all countries in the world use Arabic numerals as standard numbers.

Symbolic explanation

Numbers are both unfamiliar and familiar terms. It consists of ten letters from 0 to 9. Numbers not only include counting, but also have rich philosophical connotations.

1: It can be seen as the number "1", a stick, a crutch, an upright gun, a candle and a one-dimensional space. ...

2. It can be seen as the number "2", a wooden horse, a kneeling person, a steep slope, a slide and a goose. ...

3. Can be seen as the number "3", two fingers, breasts, cross-eyed, branches, inverted W. ...

It can be seen as the number "4", a squatting person, a small sailboat, a small red flag and a knife. ...

5: Can be seen as the number "5", big belly, little ass, notes. ...

6. It can be seen as the number "6", a tadpole, a person with a head and an arm exposed. ...

7. It can be seen as the number "7", crutches, small tables, benches, fork roads, T-shaped objects and sickles. ...

8. It can be seen as the number "8", the mathematical symbol "∞", peanuts, collars and snowman. ...

9: Can be seen as the number "9", a person sitting next to it, a small bud. ...

0: can be regarded as the number "0", chubby person, round "○", sole, feet, two-dimensional space, thin face, eggs. ...

Numbers can be divided into real numbers and imaginary numbers, real numbers can be divided into rational numbers and irrational numbers, or into integers and decimals, and any rational number can be converted into digital form.