Adding
25 + 55
= 80
4 + 3
= 7
5 - 2
= 3
10 - 5
= 5
17 + 19
= 35
7 + 7
= 14
20 - 15
= 5
35 - 10
= 25
25 + 25
= 50
62 + 33
= 95
56 - 24
= 32
66 - 42
= 24
178 + 153
= 331
167 + 80
= 247
172 - 50
= 222
164 - 55
= 109
166 + 153
= 319
143 + 178
= 321
174 - 149
= 25
157 - 68
= 89