addition with regrouping 2 digit numbers

3:20

3:56

7:59

6:26

15:37

5:41

3:47

9:54

7:32

3:25

5:27

4:35

2:24

10:10

18:35

1:10

8:51

12:44

3:38

4:04

3:51

6:45

5:36

1:12

5:51

9:59

9:11

4:20

7:08

6:03

3:15

10:55

2:33

3:28

00:59

5:34

8:13

5:49

4:12

3:40

3:04

6:07

4:44

3:10

2:42

1:32

8:19

7:26

4:30

4:13

6:26

7:32

9:54

9:11

7:09

2:43

16:11

2:24

4:40

2:00