Estimating Sums Worksheet

Estimating Sums

Read each question carefully. Estimate the sums using the specified rounding method or a suitable method of your choice. Show your work where requested.

1. Estimate the sum of 4,789 + 2,112 by rounding each number to the nearest thousand.

2. Which is the best estimate for 15.8 + 3.1 + 8.9 by rounding to the nearest whole number?

3. When estimating the sum of 124 + 379 by rounding to the nearest hundred, the estimated sum is  .

4. To estimate the sum of 7.23 + 4.89 + 1.12 by rounding to the nearest whole number, you would round the numbers to  ,  , and  . The estimated sum is  .

5. A student rounded 345 to 300 and 678 to 700 to estimate their sum. Explain if this was an appropriate rounding strategy and why.

6. Estimate the sum of 1/3 + 5/6 + 7/8. Explain your strategy.

7. Rounding 1,450 to the nearest thousand gives 1,000.

8. When estimating 0.98 + 0.05, rounding to the nearest tenth gives an estimated sum of 1.1.

9. Use the number line below to estimate the sum of 2.3 + 1.8 by rounding each number to the nearest whole number. Mark the rounded numbers and their estimated sum on the number line.

10. Estimate the sum of 17.6 + 32.1 by rounding to the nearest ten. Show your work.