Lego Math: Grouping and Getting Ready for Multiplication

We have been having a lot of fun using 1 x 1 LEGO® bricks for math! Owen (age 4.5) has been using them to play a roll and count game.

Here’s an idea for using LEGO® for a pre-multiplication activity. Gresham is using Making Math Meaningful for 2nd grade math. Right now, he is working through a chapter on grouping. I really recommend Making Math Meaningful, but you can teach this concept no matter what curriculum you are using.

For this activity, give your child a number of Legos to start with. It doesn’t need to be a number that divides evenly. “Leftovers” are okay.

Example: Start with 30 LEGO® bricks.

Lego Math: Grouping and Getting Ready for Multiplication

Make groups of four.

Lego Math: Grouping and Getting Ready for Multiplication

Then, write down your results using grouping notation.

7 (4) + 2 = 30

Or, 7 groups of 4 plus 2 leftovers = 30

Lego Math: Grouping and Getting Ready for Multiplication

Then, repeat by grouping 30 by other numbers. Gresham’s book had him group by 4, 7, 3, and 10.

Repeat with a variety of numbers – some that group evenly (such as 25 by 5’s) and some that don’t.

Why I love this activity:

  • It presents a new way to think. Up until now, Gresham has mostly been working with adding, subtracting, estimating, and measuring. Grouping is a new way to think! How many 5’s can I make with 20? If we have 16 pieces of candy, how many can each of us have? Introducing new skills keeps kids engaged.
  • Grouping with LEGO® bricks is so hands on and visual that it doesn’t feel “hard”, and yet it provides practice with more complex number concepts. The Making Math Meaningful book has had Gresham working on the same skill of grouping in slightly different ways over the past several lessons. At first, he was just building the LEGO® towers to be the appropriate size and being surprised by the answers, but now he can predict what the answer will be. “Oh, there will be 4 5’s in 20!”
  • Grouping lays the groundwork for understanding multiplication and division. Aidan tried to explain multiplying to Gresham a few weeks ago, and he was very resistant. However, every time he writes down grouping notation he is using the concept of multiplication without even realizing it! We did a multiplication activity with LEGO®’s (post coming soon!), and it was easy for him to grasp after all that grouping.

Be sure to check out the rest of the LEGO® math series!

LEGO® is a trademark of the LEGO® group of companies which does not sponsor, authorize, or endorse this site.


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  1. Florisse Dec 10, 2013

    7(4) +2=30 Not 31

    1. Sarah Dec 10, 2013

      Thanks for catching that mistake! I updated the post to fix it.

      1. Florisse Dec 12, 2013

        Love your blog!!! A treasure trove of ideas!

  2. Angelia Dec 30, 2013

    This is really cool! My sons will love it! Thanks! I have included your blog for my homeschool compilation.

    Thank God for your wonderful ideas and strong biblical insights as you homeschool. Have a blessed New Year!



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