Mathematics, the father of natural science, originated from the great invention of natural numbers used for counting.

Humans first gave birth to the vague concept of "number". When they come back from hunting, their prey may or may not be there, so there are two concepts of "yes" and "no"

Later, social groups developed into tribes. Tribes are made up of families with few members. The so-called "you" can be divided into one, two, three and more (some tribes don't even have three). Any quantity greater than three is understood as "many" or "a pile" or "a group".

About/kloc-0.0 million years ago, glaciers retreated. Some stone age nomadic hunters started a new way of life-farming in the mountains of the Middle East.

They encountered some problems, such as how to record the date and season, and how to calculate the number of grains and seeds collected. Only "one", "two", "three" and "many" are not enough. Between the Tigris and Euphrates rivers and around them, it is called Mesopotamia-marking trees or stones to record the passing days.