ADDITION
5+5
10
9-5
4
13 + 13 - estimate by rounding nearest 10th
10 + 10 = 20
5 x 2
10
12 + 12
24
30
20-15
5
25 + 25 - nearest 10th place
30 + 30 = 60
12 x 12
144
24 - 17
7
40+65
105
45-26
19
325 + 260 - nearest 100 place
300 + 300 = 600
25 x 6
150
14 x 3
42
400+400
800
436-327
109
359 + 585 - nearest 100 place
400 + 600 = 1000
36 x 8
288
300
570+610
1180
680-545
135
648 - 687 - nearest 10th place
650 - 690 = 40
30 x 4
120
292 + 328 - round sum to nearest 100th place
600