Show:
(1) Addition of Positive Integers
(2) Addition of Negative Integers
(3) Addition of Negative and Positive Integers
100

2+4

6

100

-2 + 1

-1

100

-1 + 1

0

200

14+7

21

200

-6 + 4

-2

200

-6 + 16

10

300

20+43

63

300

(-2) + (-2)

-4

300
1 + (-67)

-66

400

67+68

135

400

-400 + 670

270

400

(-27) + (-30)

-57

500

940+467

1407

500

(-1000) + (-650)

-1650

500

(-45) + (-72)

-117