Mental Addition
5 + 7
12
12 - 7
5
23 + 64 =
87
821 - 567 =
254
12 + 13
25
24 - 12
12
186 + 192 =
378
725 - 518=
207
18 + 22 + 5
45
79 - 23
56
234 + 121 + 100
455
615 - 183 =
432
30 + 5 + 7
42
81 - 34
47
1189 + 2198 =
3,387
200 - 70 - 30 =
100
234 + 234 + 110
378
225 - 42 - 120
63
43,555 + 32,980
76,535
930 - 75 - 30
825