estimating subtraction problems

9:11

14:28

10:15

19:58

19:13

11:25

4:29

4:44

14:28

9:10

9:11

14:28

9:58

9:55

13:34

11:59

5:13

کوتاه

45:17

13:34

1:27

1:11

10:41

10:42

کوتاه

کوتاه

37:18

4:09

6:33

1:53

2:16

4:23

8:22

3:39

3:38

6:12

21:38

14:28

20:43

9:32