1. Play games to ask and answer children.

2. Make two thin irons that can be covered with beads (such as abacus beads) and let the children go on stage to confirm their understanding.

3. Each person makes a set of (40) thin bamboos.

4. Recite the addition and subtraction within 20.

Let each family buy a picture of addition and subtraction and stick it in a conspicuous position at home.

6. Stick addition and subtraction in front of the classroom.

7. If you have multimedia, you can search online for children's songs with addition and subtraction within 20 minutes.