1. scale model, such as understanding the relationship between length and weight, such as 1 meter equals 100 cm, 1 kg equals 1000 g, etc.

2. Percentage model. Such as understanding the meaning of percentage and the method of calculating percentage.

3. Fractional model. For example, understanding the meaning of fractions, simplifying fractions, adding, subtracting, multiplying and dividing fractions, etc.

4. Area and volume model. For example, know the area of a plane figure and the volume of a three-dimensional figure.

5. Motion model. For example, understand the relationship between speed, time and distance, such as speed = distance ÷ time and so on.

6. Equation model. For example, by using equations to solve mathematical problems.

7. Statistical model. Such as cognitive charts, data analysis and statistics, frequency distribution, etc.