The Best Decomposing Math Center Activities

I’m writing to share decomposing math center activities you can use to reinforce ideas of decomposing. Keep reading to grab the freebie at the end of this blog post.

I have shared decomposing activities before. I love teaching decomposing! It’s a tricky concept, but there are TONS of activities you can use to teach this skill to primary learners.

What’s Decomposing?

Decomposing is breaking a number into parts. Students are used to working with whole numbers (using objects to make 5) and will now learn that numbers can be broken into parts (2 and 3 are the same as 5). They will decompose numbers drawing and using objects. Some students will be ready to write equations but when we first learn about decomposing, they use words to explain their thinking.

Students are expected to decompose numbers within 10, find the number that makes 10 and solve word problems by decomposing. The goal is to develop students’ understanding of numbers, such as learning that numbers are flexible.

Strategies that Work

Here are some strategies you can use to help your students decompose:

1. Teach them the language by modeling – show students how to decompose a number by modeling how to do it. Think aloud as you decompose a number. Invite students to share what they notice or what confuses them and use this time as an opportunity to clarify any misunderstandings. Some new vocabulary words you want to use when modeling how to decompose is decomposing, joining and separating.
2. Allow students multiple opportunities and a variety of mediums to show their thinking. Allow them to draw pictures, act it out using their whole bodies and fingers, and using objects.
3. Teach students how to use learning tools such as part-part-whole, number bonds, and ten frames to model how to decompose numbers.

Activities for Decomposing Numbers

Here are some activities for providing students meaningful opportunities to decompose numbers.

Show It 3 Ways

Students pick a number card. They decompose the number using cubes by breaking the cubes into 2 parts. They write an equation or number sentence and draw a picture.

Slide And Decompose

Students put 5 or 10 counters or objects  in the circles. Have students slide some counters in the top and bottom rectangles. They write how they decompose the number as an equation or number sentence.

Part-Part-Whole Mat

Students pick a number and decompose it using a Part-Part-Whole Mat.

Number Bonds

After they pick a number, students decompose that number using a number bond.

Huge Number Bond

Bigger can sometimes be better! Students can decompose a number using a big number and write how they decomposed the number on the table (or recording sheet!)

Flip and Decompose

This game is so much fun! Students flip a card and use a ten frame to show how many more objects they need to make 10.

They also practice making 5.

Build and Write the Missing Number

Students choose an equation and use a ten frame to solve the missing number.

Make It 3 Ways

This activity was a huge hit with my students! It’s always the simplest games that get my students the most excited! Students pick a target number and decompose that number in 3 ways. You can have them use objects or draw a picture. Then they wrote a sentence or an equation to show how they decomposed the number.

Puzzles, Puzzles, and Puzzles!

My students love puzzles! This is a great partner game and will get your students talking about decomposing. They pick an equation and match it under the correct number.

Solve and Cover

This is a great game to get students thinking about the different ways to decompose a number. They pick a domino, add the numbers to find the sum, and cover the answer on the game board.

Spin and Solve

My students love this hands-on game! Especially since I purchased plastic spinners and they don’t have to use a pencil and paper clip anymore (it’s the little things that get them excited!). They spin the spinner, figure out how many more they need to make 10, and cover the ten frame that displays that number on the game board.

Make 10!

Students count the coins in the piggy bank and use a ten frame to show how many more they need to make 10.

Math Talk Mat

This is a great activity to help students to develop the vocabulary for decomposing numbers. I teach English as a Second Language and this activity helped with seeing and saying “part” and “whole” numbers. Students pick a number bond and model it using a part-part-whole mat. Then they write how they decomposed the number and share their work with a partner.

Act it Out!

There are 3 Act it Out! word problem mats. Students act out the word problems using objects and record their decomposition by writing an equation or number sentence.

Make 5! Board Game

This is a partner game. One student flips a card over and says if the fingers show a way to make 5 or not make 5. If it is a way to make 5, they move their pawn up one spot. They continue to play until they reach the end.

Phew! That’s a lot of decomposing games!

Get Decomposing Math Centers

Do you want all the decomposing math center activities? Click the image below to purchase at my TpT store!

Decomposing Numbers Math Center Freebie

You can never have too many math center activities. Here’s a freebie from my Decomposing Math Center packet. You can grab this low-prep activity by completing the form below. 

What are some other decomposing activities you have used in your instruction? Let me know in the comments section below.

Happy teaching,

Tee