Mathematical formula is an expression method that people find some connection between things in nature and express it in some way. It represents the equal or unequal relationship between the quantities of different things in nature, accurately reflects the internal and external relations of things, and is the basis for us to reach another thing from one thing, so as to better understand the essence and connotation of things.

Introduction to primary school mathematics:

Primary school mathematics is to teach children a series of knowledge about number, four operations, the calculation formula of figure and length, unit conversion and so on through textbooks, which lays a good mathematical foundation for junior high school and daily life calculation.

Frieden Noel, a Dutch educator, said: "Mathematics comes from reality and must be rooted in reality and applied to reality." Indeed, modern mathematics requires us to observe the world from a mathematical perspective and explain the world in mathematical language.