1. To play hard cards, each card has the following problems. You can use colored pens, but it is recommended to use only two colors. Don't let colors and numbers dominate everything.

2. Start practicing the cards in order, and the children will answer the questions orally, and then they will be out of order. Do not move on to the next step until you are proficient.

3. Take out 3+2 and 2+3 cards at the same time, analyze the reasons of the same number, and let the children understand additive commutative law slowly (other reasons are the same).

4. Ask the children to find the cards whose sum is 5 and learn the decomposition of 5: 1+4, 2+3, 3+2, 4+ 1. In fact, it will be difficult for children who have just started school to answer how many 5 can be divided into (the same as 4, 3 and 2). Don't underestimate that this simple division will affect the speed of addition and subtraction in the future, such as 9+4=? Divide 4 by 1+3, and round up 1 with 9 to get 13 quickly.