A mathematical mind map can be drawn like this. The fourth grade mathematical mind map includes the meaning and nature of decimals, observation objects, operation rules, four operations and so on. The main knowledge points are summarized here.

Concept is the cornerstone of learning mathematics. Learning concepts (including theorems and properties) requires not only knowing why, but also knowing why. We should not only remember the concepts, but also understand their background. For every definition and theorem, we must know where it comes from and where it is applied. Only in this way can we learn math well.

Fourth grade mathematics knowledge points:

1 ton =1×1000 =1000 kg; 1 kg =1present1000 = 0.001ton

1k g = 1x 1000 = 1000g 1g = 1÷ 1000 = 0.00 1k g。

Length:1km =1×1000 =1000 m1m =1÷1000 = 0.00/kloc-.

1 decimeter =1×10 =1cm =1÷10 = 0.1decimeter.

1 cm = 1 ×10 =1mm = 1÷ 10=0. 1 cm.

1 decimeter = 1 ×100 =100 mm/mm =1÷100 = 0.01decimeter.

1 m = 10 decimeter =100cm =1000 mm1mm = 0.1cm = 0.01decimeter = 0.00/.

Area:1m2 =1×100 =100m2 =1m2 =1÷100 = 0.0/kloc-0.

1 square decimeter = 1 x100 =100 square centimeter1square centimeter =1\ u100 = 0.01square.