## The first stage

The first stage: the formation period of mathematics (in ancient times-the sixth century BC), this is the period when mankind established the most basic mathematical concepts. Human beings have gradually established the concept of natural numbers, simple calculation methods, and recognized the most basic and simple geometric forms. Arithmetic and geometry have not yet been separated.

## The second stage

The second stage: elementary mathematics period, constant mathematics period (6th century BC-early 17th century AD) the basic and simplest results of this period Forming the main content of middle school mathematics, it lasted about two thousand years. During this period, the main branches of elementary mathematics gradually formed: arithmetic, geometry, and algebra.

## The third stage

The third stage: the period of variable mathematics (from the beginning of the seventeenth century to the end of the nineteenth century). Variable mathematics was born in the 17th century and has undergone two decisive major steps. : The first step is the creation of analytic geometry; the second step is the creation of Calculus.

## The fourth stage

The fourth stage: the period of modern mathematics (beginning at the end of the nineteenth century), the beginning of the modern stage of mathematical development, with all its foundations ------ --Characterized by profound changes in algebra, geometry, and analysis.

## Research results

### Introduction

The Chinese nation is a nation with a splendid culture and a long history. Among the splendid cultural treasures, mathematics is in the history of the development of mathematics in the world It also has many dazzling auras. Many of the research results of arithmetic in ancient China have bred advanced thinking methods that were later designed by Western mathematics. In modern times, many world-leading mathematics research results are named after Chinese mathematicians.

### Li's constant formula

The research results of the mathematician Li Shanlan in the field of series summation are named "Li's constant formula" in the world.

### Fahrenheit's Theorem

"Fahrenheit's Theorem" is the research result of Hua Luogeng, a famous mathematician in my country. Fahrenheit's theorem is: the semi-automorphism of a body must be an automorphism, an automorphism or an antimorphism. Mathematician Hua Luogeng’s research results on complete trigonometric sums are called "Fahrenheit theorem" by the international mathematics community; in addition, the method he and mathematician Wang Yuan proposed for multiple integral approximate calculations is internationally known as the "Hua-Wang Method".

### Su's Cone

Mathematician Su Buqing's research results in affine differential geometry are named "Su's Cone" internationally. One of the most wonderful discoveries made by Academician Su Buqing on affine differential geometry is that he constructed an affine-invariant fourth-order (third-order) algebraic cone for general curved surfaces. In the affine surface theory, there are many covariant geometric objects for people, including 2 principal tangent curves, 3 Darboux tangents, 3 Segre tangents and affine normals, etc., which can be derived from this cone and its The three sharp-pointed straight lines are reflected in a beautiful way, forming a very fascinating composition. This cone is named Su's cone.