The first volume of grade three: collocation and competition, and the second volume of grade three: simple collection and equal substitution. A simple set is to divide it into two parts first and then find out the similarities between them. Equivalent substitution (through balance).

For example, a watermelon is equal to four weights, four apples are equal to 1 weight, and a watermelon is equal to several apples. The first volume of grade four: reasonable arrangement of time, the second volume of grade four: planting trees, and the first volume of grade five: coding, understanding the meaning of ID card and postal code. And can be coded simply.

Course introduction

Make students master collocation methods and realize the value of orderly thinking in solving problems; Let students explore the methods and results of collocation through activities such as posing, drawing, linking and writing, and experience the methods of classification, step by step counting and combination of numbers and shapes; Let students understand the close relationship between mathematics and life, experience the process of mathematization and feel symbolic thinking.