Estimation sums up to 100
Use rounding to estimate the answer to the addition problem.
Check
64 + 19
???
100
70
80
90
40
50
39 + 29
???
100
70
80
90
40
50
51 + 29
???
100
70
80
90
40
50
41 + 58
???
100
70
80
90
40
50
53 + 31
???
100
70
80
90
40
50
27 + 38
???
100
70
80
90
40
50
23 + 49
???
100
70
80
90
40
50
28 + 39
???
100
70
80
90
40
50
66 + 19
???
100
70
80
90
40
50
42 + 32
???
100
70
80
90
40
50
26 + 51
???
100
70
80
90
40
50
22 + 77
???
100
70
80
90
40
50
45 + 41
???
100
70
80
90
40
50
77 + 9
???
100
70
80
90
40
50
28 + 18
???
100
70
80
90
40
50
19 + 33
???
100
70
80
90
40
50
61 + 28
???
100
70
80
90
40
50
47 + 39
???
100
70
80
90
40
50
39 + 39
???
100
70
80
90
40
50
24 + 18
???
100
70
80
90
40
50
Check
OK