estimate the sum or difference by rounding the nearest one
9.87
+4.05
= appr 10 + 4 = appr. 14
To estimate the sum by rounding to the nearest one, you can round each number to the nearest whole number and then add them together.
Rounding 9.87 to the nearest whole number, we get 10.
Rounding 4.05 to the nearest whole number, we get 4.
Adding them together, 10 + 4 = 14.
Therefore, the estimated sum of 9.87 + 4.05 by rounding to the nearest one is 14.