Composing Numbers & Decomposing Numbers

Posted on Oct 20, 2020

Today, you can learn ways to help students and eager learners to understand two new terms. Even though these terms might be very big for little ones, you can make them understandable with this guide and the fun math video below. Our terms are composing and decomposing numbers. These terms won’t be so hard for your young learners to understand once they get the hang of it.

What Is Composing Numbers?

Composing numbers will be readily learned if you explain that it involves putting together two or more numbers. You could relate it to “building” a bigger number. Kids love to build things, so this may spark their interest.

Start with two numbers to make the process easier for the children and have them “build” or compose them. All they have to do is combine them to make a larger number. You could tell them that when they are composing numbers, always look at both of the individual numerals. Their final answer will always be larger than either of the two they are composing.

Composing Numbers Example

You can compose a number in more than one way!

The other great thing you can teach your young learners is that there is no limit on how many numbers they put together. They can compose two, three, or even four numbers. For now, you might want to stick with no more than three numbers when working with young ones.

How to Decompose Numbers

Teaching young learners about decomposing numbers involves breaking a larger number into smaller numbers. Help your students see that there is often more than one way to decompose a number. For example, the number six can be split up into the numbers three and two or five and one. Larger numbers can be decomposed into more sets.

Composing and Decomposing Numbers in Everyday Life

Since kids will learn best when using their hands and objects, get a few objects to show them how this concept of composing and decomposing numbers works.

You could use pencils to illustrate your point and make a little game out of it. You could let your young learner select a few pencils to hold in their hand, then you can put a few in your hand. Now, explain that you’re going to compose them by putting them together. You can count the bunch of pencils as you put them in a pile together. They will get extra practice with their counting skills too!

Now, switch around the pencils so that you’re holding the amount they had and they are holding the amount you had. Place them together and recount the pencils. They will see the answer is the same. It’s important to stress that no matter what “position” the number is in, the result is the same.

Decomposing numbers with kids can be just as fun. Get a group of twelve pencils and separate them into two piles. Demonstrate to your young learner that this group of pencils can be split up into several different arrangements. Let them help you split them up in different ways. It would be helpful if you wrote down the various numbers that you can take apart so learners can see what numerals make up the numbers. They may notice that larger numbers can be decomposed into more groups or sets, while smaller numbers might only be decomposed once or twice.

Composing with 5-Frames and 10-Frames

10-Frames and 10-Frames can be very helpful when composing numbers

Check Out Math Videos for Kids

Now is a great time to wrap everything neatly together with a video on these concepts. Our fun kid’s math videos will help your young learners understand what you’re teaching them. You can tune in every week for more great videos!


Hey there!

Did you know that Scratch Garden has a 2nd Channel?

It's true! We have created a whole other channel on Patreon! Patreon allows creators like Scratch Garden to offer a kind of membership for special fans like you. In exchange for your support, you can access monthly patron-only content like behind-the-scenes videos as well as more hilarious Blooper Videos

For as little as $2/month you can watch all these videos AND help support Scratch Garden to keep making great fun educational content. 

Check out our 2nd Channel to find out more!



Leave a Reply