What are the playing methods of playing cards?

A deck of playing cards can play many things that kindergarten mathematics needs to master, such as classification, operation, comparison, sorting and so on.

You may not go to kindergarten, but don't leave behind what you can learn at home. In elementary school, I scored 24 points. Only 40 cards (1- 10, * * *) are selected, and each person holds 20 cards, each with 2 cards, and the operation order is randomly used, so the result of 4 cards is 24.