CRA for Composing and Decomposing Numbers

Written by Donna Boucher

Donna has been a teacher, math instructional coach, interventionist, and curriculum coordinator. A frequent speaker at state and national conferences, she shares her love for math with a worldwide audience through her website, Math Coach’s Corner. Donna is also the co-author of Guided Math Workshop.

Okay, I’m having trouble finding different ways to say “composing and decomposing numbers” in my post titles! But seriously, it’s just THAT important, so I keep writing about it. Our Kinders and Firsties should be doing these types of activities extensively, so it’s important to find lots of different ways to approach the skill.

Today I present Clothespin Count. Students use strips that have dots showing 5 (pictured below) through 10. Choose the number that your kiddos need to work on. They don’t all need to be working on 5; that’s how you differentiate this activity. You’ll need two different colors of clothespins, and you need as many of each color as there are dots on the card. So, if kids are working on 5, they need 5 of one color and 5 of the other. Students use a random number generator (several options shown below) and put that many of one color of clothespin on their strip. Then they complete the number with the other color clothespin. Place a Math Talk card in the workstation that says, “____ and ____ make ____” so they use the correct mathematical language to describe the combination they have made. So in the first picture shown, the student would say “1 and 4 make 5.” They draw another card (or roll the number cube again) and make another combination.


Using a number card for the random number generator adds an abstract (symbolic) component to the activity. Now you have concrete (clothespins), representational (the dots), and abstract (the numeral).

Use number cubes with dots for the random number generator and kiddos also get to practice subitizing.  Of course, you can only use the number cube when working on combinations of 6 through 10.  And if you use it for 7-10, they won’t be able to get all the combinations.  Make sense?

This shows how students can show their work on the B & W version (download below). As they progress, they can write the actual number sentence instead of using “and” and “make”.

Copy and cut apart the strips with colored dots for students to use with the clothespins in their workstations. Strips are included for the numbers 5 through 10. Place copies of the B & W recording sheet for students to use to show their work.

Easy peasy, right?  Click here to grab your copy.  Enjoy! 

Like the number cards shown in the pictures?  Grab them here.

20 Comments

  1. Amy B

    SUPER idea! Thanks Donna!
    Amy Burton

    Reply
    • Donna Boucher

      You’re welcome, Amy. Do you go back soon?

      Reply
  2. KinderKarla

    Super easy idea and great practice! Love it! Thanks for the great ideas! I can never have enough activities for composing and decomposing numbers!

    Reply
    • Donna Boucher

      I know, right? Glad you like it. 🙂

      Reply
  3. Corinna

    Another fabulous idea to add variety for composing and decomposing numbers! Thank you once again!

    Reply
    • Donna Boucher

      You’re welcome, Corinna! I’ll TRY to keep coming up with more.

      Reply
  4. HighDesertGal

    Love this idea. Did you paint your clothes pins or were you able to find them in primary colors somewhere?

    Reply
    • Donna Boucher

      I found them! They are small, plastic, and came 75 to a package for a dollar. I want to say it was the 99 Cent store, but I visited a couple of dollar stores that day.

      Reply
    • HighDesertGal

      Thanks. We don’t have a 99 cent store but I’ll check some of the other dollar stores here.

      Reply
  5. Sherri Boutilier

    Great idea! Thanks for sharing!
    Sherri

    Books, Blocks and Baskets

    Reply
    • Donna Boucher

      You’re welcome!

      Reply
  6. Kelly

    I love this, thank you!! I can’t wait to use this with my first graders 🙂

    Kelly
    First Grade Fairytales

    Reply
    • Donna Boucher

      They should love it!

      Reply
  7. Kinderaffe

    Going back to kindergarten after 5 years away! This will be perfect! I am one of you newest followers! Thx!
    Sara
    Kinderaffe2ndgraders.blogspot.com

    Reply
    • Donna Boucher

      Ooh, have fun with the Kinder babies! I’m following your blog now, too. 🙂

      Reply
  8. Anonymous

    Donna- I’m still rootin’ around your site (love it!), but do you have some fun ideas for decomposing numbers at 5th grade??
    Thanks!
    Mickie
    [email protected]

    Reply
    • Donna Boucher

      Hey, Mickie. That’s a toughie. I think composing and decomposing is more prevalent in the primary grades to lay the foundation for what they’ll be doing with the skill in the upper grades. For example, when you regroup to subtract, you need to have an understanding of decomposing numbers. Or when you use the area model for multiplication, you’re using what you know about decomposing. Of course, you can still do a number of the day and have kiddos find different ways to make the number. And in place value, it’s important for kiddos to know that numbers can be decomposing into different groups of thousands, hundreds, etc. I’ll think about it and see what I can come up with. 🙂

      Reply
  9. jssscocosophie

    Found you through Pinterest, thanks for another way for composing and decomposing practice!

    Reply
    • Donna Boucher

      You’re so very welcome! 🙂

      Reply
  10. Paola Galarza

    awesome thanks!!

    Reply

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