Estimate the sum of 23 and 71
Estimation:
23 --> rounded to 20
71 --> rounded to 70
70 + 20 = 90. I rounded both numbers down so the exact sum must be only a little greater than my estimate.
23 would be 20
71 would be 70
20 + 70 = 90
The actual answer is:
21 + 71 = 92
Hope this helps!
Bye :)