1 ~ 6 grade mathematics key knowledge can be summarized as: addition, subtraction, multiplication and division, calculation of fractions and decimals. Understand graphics and calculate perimeter and area. Understand the basic concept of probability, and master the analysis methods of statistical charts and data. Learn to use letters to represent numbers and master the solution of equations. Learn to use what you have learned to solve practical problems and improve your thinking ability and problem-solving ability. These key knowledge is the core content of primary school mathematics, which needs students to study and master seriously.