1, arithmetic:

Arithmetic is the oldest, most basic and primitive part of mathematics. It studies the properties and operations of numbers. The oldest mathematics, arithmetic, is formed by accumulating and sorting out the properties of numbers and the experience of four operations between numbers in the application process. All mathematics in ancient times was called arithmetic, and modern algebra and number theory originally developed from arithmetic. Later, the concepts of arithmetic and mathematics appeared, which replaced the meaning of arithmetic and included all mathematics, and arithmetic became a branch of it.

2. Geometry:

Geometry, abbreviated as geometry, is a branch of mathematics that studies the relationship between spatial regions.

Because of the needs of human production and life, geometry came into being. In primitive society, human beings have accumulated a lot of knowledge about the shape, size and position of objects in their production and life. For example, ancient people knew the shape and size of prey, and remembered the distance between the residence and the hunting ground, as well as the location of the hunting ground in the residence.