+
-
100

1+1=?

 2

100

0-0 =?

0

200

2+3 =?

5

200

3-4

-1

300

4+4 =?

8

300

50-40 =?

10

400

5+9 =?

14

400

76-75 =?

-1

500

1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000+999 =?

1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000999

500

123-3 =?

120