Expression refers to the use of mathematical symbols and numbers to express quantitative relations. In primary school mathematics, formulas are usually used to solve simple mathematical problems, such as addition, subtraction, multiplication and division. An expression usually consists of three parts: operators: for example, plus sign (+), minus sign (-), multiplication sign (×), division sign (÷) and so on. Numbers involved in operation: These numbers can be numbers, letters, symbols, etc. Operation result: the result obtained by the operator and the numbers involved in the operation.
For example, the following simple formula: 2+3=5, where 2 and 3 are the numbers involved in the operation,+is the operator and 5 is the result of the operation. Formulas are very important in primary school mathematics, because they are the basis for solving mathematical problems. Pupils can develop their mathematical thinking and problem-solving ability by learning how to write formulas and solutions.