Show:
Subtraction
Addition
Add tens
Add in any order
Add 3 numbers
100

2-2

0

100

4+2 

6 

100

10+10

20

100

2+3

3+2

100

3+2+1

6

200

7-6

1

200

5+5

10

200
20+30

50

200

9+5

5+9

200

5+3+4

12

300

13-9

4

300

9+8

17

300

10+70

80

300

10+9

9+10

300

6+7+8

21

400

11-5

6

400

20+5

25

400

40+50

90

400

6+7

7+6

400

10+4+5

19

500

20-9

11

500

100+100

200
500

20+60

80

500

11+11

11+11

500

20+50+30

100