Objective: The main reason is that students often confuse the conversion of units, and some have no concept of units. This mind map can be well applied.
Comments:
1, middle picture: A child is carrying a burden, and all the units are in the basket. Because the load must be balanced, unit conversion is also the concept, and conversion is also equal balance. This is the moral of this middle picture. When you see the load, you immediately think of the unit.
2. The first branch: expand by length unit, which is the most basic unit, and also mark the relationship between them.
3. The second branch: according to the unit area, the relationship between them is also listed.
4. The third branch: based on the measuring range, it mainly talks about how to use it when measuring the length and area.
5. The fourth branch: based on calculation, it mainly explains the perimeter and area of squares and rectangles.