This candy store math problem is a fun way to introduce 2nd and 3rd graders to the geometric model for multiplication, and kids really don’t need to know much about multiplication to benefit from this. The week after we built our Lego multiplication graph, I told Gresham that we were going to use the same LEGO® bricks to design candy boxes. He was pretty excited about that idea!

I gave him our colored 1 x 1 Legos, white LEGO® bricks for building the “boxes,” and a piece of paper with the numbers of candies that needed to fit inside each different size of candy box that we were going to design.

We designed boxes to hold 8, 15, 24, and 30 candies. I told Gresham that the boxes had to be squares or rectangles, but other than that, he could design the dimensions!

He was able to figure out the first box very easily: 2 x 4 = 8 candies. I showed him how to graph the result on graph paper.

Then he worked on a box to hold 15 candies. This proved to be a little more difficult, which I knew it would be! I chose the number 15 to make him think a little. He was totally stuck on wanting the box to be 2 candies wide. I suggested that he try another width, so he chose 3. And it worked! So fun to see the light bulb go on.

For 30 candies, Gresham did 3 x 10. I challenged him to try to make a box that was closer to a square shape rather than such a long rectangle. He came up with 5 x 6. We were able to talk about how 3 groups of 10 are equal to 5 groups of 6.

Here are his final results:

Another day, we used our candy box designs for a follow-up math problem – post coming soon on that one!

Be sure to visit the rest of our Math with LEGO® series!

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1. ##### jENNIFER Jan 9, 2014

You have no idea how much I needed to see this post tonight. I feel brainless helping my 3rd grade son about multiplication. It's not clicking as quickly as it should and we're both frustrated. He, too, is obsessed with the almighty Lego so this will be our new approach starting tomorrow! We moms of boys need each other don't we?!

1. ##### Sarah Jan 10, 2014

Thanks for your comment! I'm glad you found it helpful. You also might want to look back at my Lego post on grouping - it really helps develop the concept of multiplication from a different angle, and it's also very visual and hands-on so he won't know he's learning multiplication! Grouping helped my son a lot. Good luck!

2. ##### Anna@The Measured Mom Jan 12, 2014

Love your creative learning ideas! I don't usually see you at linky parties, but if you're ever up for linking, we'd LOVE to see your stuff at the After School Linky. Yours are just the kinds of posts we want our readers to see and learn from. (Starts every Monday.)

3. ##### Melinda Jan 14, 2014

AWESOME! We're getting ready to learn multiplication, too. And I absolutely love this idea. I have a girl who is a tactile learner who loves Legos. This is perfect for her! Thank you so very much.

Hugs,
Melinda

4. ##### Amy Jan 15, 2014

This is such a great idea! I am going to share with my readers too, thanks! :)

5. ##### Tina Jan 16, 2014

This is excellent. I am going to use this activity both with my 8 year old son and my 8th grade students. Thank you so much!

6. ##### Mimi Nov 13, 2014

This is an awesome idea. As much as my grandson plays with Lego's I never even thought of trying this with multiplication. At 7 and in 3rd grade he gets really frustrated then angry when I try to get him to write the multiplication tables. He does really well with the 2-6 tables but after that it is counting on his fingers to get up to the next one and I want him to get away from finger counting. Thanks so much for this post.

7. ##### Diona Aug 29, 2015

This is amazing! I need a whole month off to just dive into your site. You have given me so many great ideas and I just had to let you know how amazing you are! Thank you for sharing!

1. ##### Sarah Sep 4, 2015

Thanks for leaving such an encouraging comment! I'm so glad that you are finding the ideas helpful!