Personally, I think we should start from three aspects: (1) dozens; (2) How to do the simplest counting; (3) Statistical cases.

(1) is a decimal number.

Let children know the purpose and history of counting.

(2) How to do the simplest counting?

{0, 1,2,3,4,5,6,7,8,9, 10, 1 1, 12, 19,20,30,40,500.

(3) Statistical cases

Count people, games, time, fingers, flowers, birds, compare sizes, find positions, guess numbers, etc. In short, we should give our children inferences about what is closest to life.