## Estimating Decimal Sums and Differences

#### 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

- Word Based Step-by-Step Lesson- Read carefully and follow the directions.
- Guided Lesson - I find this to be a great reading comprehension lesson as well. Have the kids outline what they need to do.

- Guided Lesson Explanation - Round them and then add them or subtract them.
- Estimating Sums and Differences with Decimals 5 Pack - This is best served with the numbers being vertically laid out.
- Practice Worksheet - A nice rapid fire math exercise for you. The chief is the symbol of the Poconos Warriors (Elementary) that helped me with this sheet.
- Matching Worksheet - Match the description with the estimated final value.

#### 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.