# Lesson Worksheet: Estimating Decimal Sums Mathematics • 5th Grade

In this worksheet, we will practice estimating the sum of two decimal numbers by rounding to the nearest whole number or using compatible numbers.

Q1:

Complete to the nearest hundredth.

Q2:

to the nearest thousandth.

Q3:

Estimate the sum by rounding each decimal to the nearest whole number.

Q4:

Estimate the sum by rounding each decimal to the nearest whole number.

Q5:

Madison knows how to add and subtract 0, 0.25, 0.5, 0.75, and 1. Look at how she uses these numbers to help her estimate the sums of decimal numbers. By rounding to the nearest multiple of 0.25, she finds that is about 1.75.

Estimate the sum by rounding each number to the nearest multiple of 0.25. Q6:

Charlotte bought a pencil for \$3.29 and a book for \$9.75. About how many dollars did Charlotte pay?

Hint: Round each amount to the nearest dollar.

Q7:

Estimate the sum by rounding each number to a benchmark.

Hint: Benchmarks are numbers like 0.25, 0.5, 0.75, or 1.

Q8:

Estimate the sum by rounding each number to a benchmark.

Hint: Benchmarks are numbers like 0.25, 0.5, 0.75, or 1.

Q9:

You have uploaded two videos with lengths 3.9 minutes and 5.38 minutes. About how many minutes do you need to watch both videos?

Hint: Round each number to the nearest minute.

Q10:

David is buying items on his shopping list. Estimate the total cost of the items on the list.