1. GOOD MORNING 11+5= 1+5 16 12+3= 2+3 15 calculate in ones place first
1+5=6
2+3=5
put them together
second
6+10=16
5+10=15
Add the number in the ones place first, then add the number in the tens place.

2. pigeon

3. 5-2=
Use the materials to calculate.

4. Minuend 5
5-2=

5. 5-2= 2 3 Method: 1、Put 5 circles in the frame. 2、Take away 2 circles.
Difference
5-2= 2 3
Subtrahend

6. 5 5-2= 2 3 Use the number line. Method: 1、Find 5.
2、Jump left 2 steps from 5. 5
5-2= 2 3 -2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

7. tens place
ones place
Minuend 5
5-2=

8. 5-2= 2 3 Method: 1、Put 5 circles in the chart. 2、Take away 2 circles.
tens place
ones place
Difference
5-2= 2 3
Subtrahend

9. 15-2= Use the materials to calculate. tens frame number lines
digit-order-chart

10. 15
15-2=

11. 15-2= 2 13 Method: 1、Put 15 circles in the frame.
2、Take away 2 circles.
15-2= 2 13

12. 5- 2 = 3 15-2=13 +10 +10 in difference in common counters take away
counters put at first
counters left at the end

13. 15-2= 15 2 13 Use the number line. Method: 1、Find 15.
2、Jump left 2 steps from 15.
15-2= 15 2 13 -2 -2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
5-2= 3

14. tens place
ones place 15
15-2=

15. 15-2= 2 13 Method: 1、Use circles to express 15 in the chart.
2、Take away 2 circles.
tens place
ones place
15-2= 2 13

16. 5-2= 3
15-2= 13
ones place
tens place
ones place
tens place
first
5-2=3
calculate in ones place
second
3+10=13
put them together
Take away the number in the ones place first, then add the number in the tens place.

17. Challenge1:
Calculate the number sentence and write the process.
17-5=
15-4=
18-3=

18. Challenge1:
Calculate the number sentence and write the process.
17-5=
7-5= 12
calculate in ones place
first
7-5=2
put them together
second
2+10=12

19. Challenge1:
Calculate the number sentence and write the process.
15-4=
5-4= 11
calculate in ones place
first
5-4=1
put them together
second
1+10=11

20. Challenge1:
Calculate the number sentence and write the process.
18-3=
8-3= 15
calculate in ones place
first
8-3=5
put them together
second
5+10=15
Take away the number in the ones place first, then add the number in the tens place.

21. Challenge2: Find friend Who is their best friend? 14-3 ① 4-3 ② 4+3
① ② 4+3
① 4-3
12-1
① ② 2-1
② 2-1

22. Challenge2: 18-12=? Calculate the number sentences. 18-2= 17-5= 8-2 16
18-2= =
8-2 16
7-5 12
18-12=?

23. Challenge3:
Calculate the number sentences according to the pictures. - = - =

24. × × Challenge4: 17-2= （ ） True or False.
David wants to find the result of
17-2= （ ） × 6
tens place
ones place ×

25. Challenge5:
15 -7= 13
17-7=10
18-7=11
19-7=12 13 =
15-5=10
15-4=11
15-3=12
15-2=13
15-1=14
15-0=15
What can the number sentences probably be?