How to Really See Volume - with Popcorn

I can still remember a college course I had to take called Physical Science. Little did I know- it was more about math than science! I struggled with solving a problem that involved the amount of water needed to fill an aquarium until I had one of those 'aha' moments and realized it was about volume. After that it was just a matter of using the formula for calculating volume, but I had to "understand the concept of dimensional volume".  If this was hard for me at the age of 18 or so, just imagine your third graders and this concept. 

Then along came the popcorn challenge...

Are you ready for this one! It's called The Popcorn Challenge, but it's really an exploration into volume.

One of absolutely favorite STEM challenges is all about popcorn. Kids have to use a specific amount and build something! Check this blog post for a few details!

Here's the best part!

This challenge was inspired by the cutest little book called The Popcorn Book by Tomie De Paola.
It's a great little book filled with popcorn history and trivia and then some fun facts at the end.
One of the points we bring out for this challenge is the discovery of fossilized popcorn in a cave. The scenario of the challenge is that the kids are the scientists that found the popcorn and they must design a container to carry the popcorn out safely.

After reading the book the kids take a sample of the popcorn and here's where it gets tricky.
It's the Popcorn STEM Challenge. Prep is easy- kids just need a popcorn sample and paper to make a container.

See the sample in those cups? 

That sample is only 10 pieces and the container they build must be the perfect size to hold a lot more than that. They know the number of popcorn pieces,but they can't see them. The samples are to be used to try to predict the precise size of the final container.

Kids try so many ways to use those pieces to estimate the final size. I can't tell you how many kids have measured that popcorn and then drawn the dimensions based on those numbers. They painstakingly make the box, but forget one tiny, but very important, thing. The container also has depth. Invariably they make their boxes too deep for the popcorn.

They also make them in a lot of different shapes!

Take a look:
STEM Challenge: Build a container for popcorn! This group chose a cylinder shape! More on this blog post!

Almost always there will be a group that decides to make a cylinder shaped container. The outside wall of these is fairly easy to make. It's the bottom and the top that create a problem!

STEM Challenge: Build a container for popcorn! This group chose a cube shape! More on this blog post!

Then there is the cube. For the cube to be the correct size it has to be really small. Trust me, all the ones in the photos are about three times larger than needed. Remember, the popcorn has to fit exactly.

STEM Challenge: Build a container for popcorn! This group chose an envelope shape! More on this blog post!

There's always a team that tries the envelope container, too! I think they are considering this shape because it resembles a backpack which would be a natural carrying container for the popcorn. The trouble with this shape is that is is usually too flat.

After all the containers are built I bring out the bowl with the specific amount of popcorn in it and we test all the containers. It's a time of lots of groaning- usually as soon as I get the bowl out. The kids can quickly see that their containers are way too big or too small.

Finally, we end this fabulous challenge by talking about the word volume and what it really means. This lesson is a well learned one! I use it with third graders and even when they make it to fifth grader they still remember their popcorn containers. They definitely finish this task  knowing that volume is dimensional and all directions - height, width, and depth- must be considered when measuring for volume.

This challenge is part of a Math Bundle 3-pack and 6-pack. You can see more about it right here:

Click on the book cover for The Popcorn Book to go directly to using my affiliate link and check out the books below for use in your STEM class!


  1. I learn so much from your blog posts, and I have many many MANY of your products on my wish list! Thanks for sharing your passion for STEM with the rest of us.
    Laughter and Consistency

    1. Thanks so much for your encouraging words! I love working with STEM projects with kids! They solve dilemmas in such unique ways! Thanks for stopping by!


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