Show:
Addition pt1
Addition pt2
Subtraction pt1
Subtraction pt2
100

1+4

5

100

10+4

14

100

4-2

2

100

9-9

0

200

4+3

7

200

6+4

10

200

2-2

0

200

7-3

4

300

5+5

10

300

7+8

15

300

6-5

1

300

8-2

6

400

2+6

8

400

8+9

17

400

7-3

4

400

10-3

7

500

9+2

11

500

12+13

25

500

9-7

2

500

9-4

5