Show:
Adding
Adding
Subtracting
Subtracting
100

25 + 55

= 80

100

4 + 3

= 7

100

5 - 2

= 3

100

10 - 5

= 5

200

17 + 19 

= 35

200

7 + 7

 = 14

200

20 - 15 

= 5

200

35 - 10

= 25

300

25 + 25

= 50

300

62 + 33 

= 95

300

56 - 24

= 32

300

66 - 42

= 24

400

178 + 153

= 331

400

167 + 80

= 247

400

172 - 50

= 222

400

164 - 55

= 109

500

166 + 153

= 319

500

143 + 178

= 321

500

174 - 149

= 25

500

157 - 68

= 89