In the first grade, you should lay a good foundation, draw on paper, or buy sticks. I remember when I was in primary school, the teacher gave us textbooks. I still have some questions:

4+5 1+5 2+9 6+ 1 3+2 3+7 8+9 5+6 4+7 8+5

1. For example, who is a good friend of 4, and 6 is a good friend of 4. Who is a good friend of 2 ()

a.3 b.5 c.8

2. Five on the left, 10 on the right, and how many on a * * * ()?

a. 12

Column vertical calculation

12+6

3+ 15

4+6

8+ 1 1

12+6

1 1+ 1

18+ 1

7+8

14- 12

16- 1 1

19- 1 1

19-6

20- 10