Fourth grade math map, I can still. Let me, a mathematical genius, solve it.

The friends learned two larger units for measuring land-square kilometers and hectares. When drawing the second unit mind map, I decided to sort out the square centimeter, square decimeter and square meter I had learned before, and systematically sort out each area unit from three aspects: definition, expression and examples. Mainly put the unit area in the first place, followed by square meters, square kilometers, hectares and the like marked with arrows. Similarly, when doing percentage and division, mark the center content with a circle and mark other units with an arrow. Decimals are more complicated. Here is a picture for your reference.

Colour it carefully.

I hope I can help you.