1. 2-digit number +1-digit number
Putuo District
Changzheng Central Primary School, Shanghai
Coco朱文静

2. Warm up! = 43
20＋20＝40
tens
ones
40＋3＝43

3. Task1 43 ？ =

4. = 25
tens
ones

5. Practice I = 27
tens
ones
3＋ 4＝7
20＋ 7＝27

6. Practice II = 29
3 + 6 = 9 = 29

7. Task ２　Notice !　　 = 3 6 29 9 = 25 3 2 5 = 27 3 4 7

8. Just add
in the 23’s ones place
Task ２　Notice !　　 2 4 6 = 3 6 29 9 = 25 3 2 5 = 27 3 4 7

9. Have a try 5＋4＝ 92＋4＝ 96 9 25＋4＝ 73＋3＝ 35＋4＝ 0＋37＝ 29 76 65＋4＝ 6＋42＝
5＋4＝ ＋4＝
25＋4＝ ＋3＝
35＋4＝ ＋37＝
65＋4＝ ＋42＝ 9 96 29 76 39 37 69 48

10. challenge
+ 5 = 9
The number behind the is ( ).
① ② ③ 9

11. challenge
= 9
The number behind the is ( ).
① ② ③ 9

12. 31+2=
31+5=
31+6=
31+20=
31+50=
31+60=