Compatible Numbers vs. Rounding

Your students may be learning different ways to estimate by means of rounding and compatible numbers. They may, however, struggle to understand the differences between these two estimation strategies. Let’s take a quick look at how you can easily explain these terms to your students!

Compatible Numbers

Compatible numbers make maths problems much easier to work with. These numbers are great for estimates or when you need to simplify a calculation. Compatible numbers are usually pretty close to the actual numbers you’re working with, which means you can do the maths in your head without any trouble! Many times, compatible numbers work with groups of 25.

Rounding<

Rounding is similar in the sense that it changes a number to make it easier to work with. When you use a rounding strategy, the last number will always be a zero.

Depending on the situation, it may be best to use compatible numbers, and in other cases, it may be best to use rounding. Remember, the goal is to get as close as possible to the exact answer!

Estimation Worksheets For Your Classroom! 

If your students are in need of additional estimation practice, you have come to the right place! Teach Starter has developed a set of worksheets to help your students estimate the sums and differences of whole numbers.

This teacher-created resource includes 3 worksheets for year 3 and year 4. The first page focuses on using rounding to estimate, the second uses compatible numbers and the last page can be completed by either of the strategies.

An answer key is also provided to make grading quick and easy. If your students are completing the compatible numbers worksheet, please note that different answers could be possible, and some suggested answers are included within the answer key.

How To Get Your Estimation Worksheets

If you are ready to get your hands on these estimation worksheets, head on over to the green download button. Here, you will find the quick-print PDF and editable Google Slides version to choose from. If selecting the Google Slides file, please note that you will first be prompted to make a copy of the resource to your personal drive before accessing it.

This resource was created by Kaylyn Chupp, a Teach Starter Collaborator.

More Resources For Your Estimation Lessons!

Don’t stop there! We’ve got more rounding whole numbers activities and resources that cut down on lesson planning time:

teaching resource

Estimating Sums and Differences Interactive Activity

Download our interactive activity designed to sharpen your students’ understanding of estimating sums and differences with rounding and compatible numbers.

teaching resource

Estimating Sums and Differences Differentiated Worksheets

Teach your students how to round and use compatible numbers to estimate sums and differences with this set of differentiated worksheets.

teaching resource

Estimating Sums and Differences Matching Activity and Extension Task

Guide your students to estimate addition and subtraction sentences by rounding and compatible numbers with this matching activity.