The understanding of time is the learning content of Unit 5 in the first volume of the third grade primary school mathematics published by People's Education Press. In this unit, students should establish the concept of "multiple", understand the meaning of "multiple", and master the practical methods of "how many times is one number another" and "how many times is one number". Guide students to understand the internal relationship between mathematical knowledge, the quantitative relationship of "how many times is one number" and the specific meaning of "how many times is one number".

Students also need to know some methods to analyze and solve problems, and be able to use the knowledge about "times" flexibly to solve practical problems; Make students feel the close connection between mathematics and real life, realize the application value of mathematics, and form the emotion of loving mathematics.

The learning content of this unit mainly includes the meaning of multiple (how many other numbers are there in a number, that is, how many times one number is another number), how many times one number is another number is calculated by division, and how many times one number is calculated by multiplication. Students should not only know the multiple, but also understand the quantitative relationship through drawing. When doing exercises, I found that some students wrote time as a unit, but in fact time is only a quantitative relationship and cannot be used as a unit.

What is a multiple:

Multiplication is a mathematical term that refers to the product of a number and an integer.

In other words, for two numbers A and B, if there is an integer n that makes b=na, then B is a multiple of A. If A is not zero, it means that b/a is an integer, and its division can be divisible without remainder. A multiple of 2, also known as an even number. If both a and b are integers and b is a multiple of a, then a is a factor of b, multiplied by = factor multiplied by y.

If both A and B are integers and an integer C is a multiple of A and B, then C is called the common multiple of A and B, and if C is the smallest positive integer satisfying the above conditions, it is called the least common multiple.