Show:
ADDING TO 20
SUBTRACTING TO 20
ADDING TO 50 NO RG
SUBTRACTING TO 50 NO RG
MIXED WITH REGROUPING
100

10 + 10

20


100

11-7

4

100

33+26

59

100

32-12

20

100

18+12

30

200

11+12

23

200

15-5

10

200

12+12

24

200

50-20

30

200

11+9

20

300

17+8

25

300

20-12

8

300

44+31

75

300

28-17

11

300

50-9

41

400

15+19

34

400

17-10

7

400

33+6

39

400

44-33

11

400

15-6

9

500

20+16

36

500

16-13

3

500

15+25

40

500

48-17

31

500

50-25

25