Show:
addition
subtraction
addition
subtraction
addition
100

1+1=?

1+1=2

100

10-5=?

10-5=5

100

10+10=?

20

100

20-10=

10

100

100+100=

200

200

2+2=?

2+2=4

200

8-4=?

8-4=4

200

20+20=

40

200

40-20=

20

200

200+200=

400

300

3+3=?

3+3=6

300

6-3=?

6-3=3

300

30+30=

60

300

60-30=

30

300

300+300=

600

400

4+4=?

4+4=8

400

4-2=?

4-2=2

400

40+40=

80

400

80-40=

40

400

400+400=

800

500

5+5=?

5+5=10

500

2-1=?

2-1=1

500

50+50

100

500

100-50=

50

500

500+500=

1,000