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Estimating Decimal Sums and Differences

Answer Keys Here

Aligned To Common Core Standard:

Grade 5 Base Ten - 5.NBT.7

How to Estimate Sums and Differences - Estimation is a concept in which we find the response close to the exact solution. Meaning that in the estimation, we can find an answer that can work with the problem even if it's not accurate. You can estimate the sums and the differences by rounding off the numbers to the nearest tens, hundreds or thousands. After you round off the numbers, you can use your mental math skills to solve them. Let's take two examples each for the addition and subtraction of numbers. Firstly, we have to add two numbers, 322 and 178 together. Now, let's round off the numbers to 300 and 200 respectively. If we add 300 and 200, we will get an answer of 500 and that is the estimated answer. Secondly, let's subtract 223 and 110 together. Now, let's round off to the closest hundreds, i.e., 200 and 100. Now, if we subtract the numbers, we will get answer 100 which is the estimated results. These worksheets help students learn how to get a rough estimate of the end value of decimals that are being added or subtracted.

Printable Worksheets And Lessons

Homework Sheets

Talk about knowing your math sentences. These sheets don't ask, they demand it!

  • Homework 1 - Estimate the sum of 2.420 and 7.862 by rounding to the nearest hundredth.
  • Homework 2 - Another round of the previous worksheet for you.
  • Homework 3 - More sums to focus on here.

Practice Worksheets

I highly recommend that you circle the play values in question whenever possible.

  • Practice 1 - Estimate the place value first.
  • Practice 2 - Make sure that all place values jive.
  • Practice 3 - Sometimes it will make more sense to estimate other place values first.

Math Skill Quizzes

We are really just worried about rounding to the nearest tenth and hundredth here.