STEM Challenge: Can you build a 3D structure?

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STEM Challenge. Building 3D structures.

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We’re joining in again for the second week of the 28 Days of Hands-On STEM Activities for Kids, and this week’s theme is STEM Challenges! (In case you missed it, last week’s theme was STEM Goes Green and we made this upcycled catapult.)

This is our first try at doing a ‘stem challenge’. I wanted to come up with an idea that would be age appropriate for my five and a half year old daughter Jewel, as I was worried that something too difficult would drain her awesome enthusiasm-for-all-things-science that she has going at the moment. After a lot of thought (and a little bit of inspiration from Jamie’s kid-made abacus), the STEM challenge I decided to give Jewel was: can she build a 3D structure of her choice, using just straws and pipe-cleaners (and scissors, to cut the straws and pipe-cleaners to length, if required).

The first thing Jewel asked was, “What’s STEM?”

STEM stands for Science, Technology, Engineering and Maths. There’s a huge focus on STEM around the world at the moment. Individually these subjects are all very important, but when considered as a group, they encourage the development of critical thinking, which is such an awesome skill for kids to learn. STEM for girls in particular is a huge topic. One of the goals of this blog, actually, is to demonstrate ways to make STEM fun for girls with hands-on ideas that encourage questioning and learning about our fascinating world.

So far we’ve been simplifying a lot of our learning experiences and projects by grouping them all under the science pillar of STEM. But really, many of our activities incorporate other STEM pillars too. Last week’s catapult and our earlier balance scales are activities that incorporate both science and engineering, for example.

When I explained all of this to Jewel, her eyes lit up. You could see her mind thinking, “Wow, so there’s three whole other letters we can learn about?”

Mind blown.

Her next question was, “Can I also use some sticky tape?”

Haha, that’s against the rules of this challenge kiddo. Maybe next time, but for now, see how you go with just these three basic materials.

Suitable for

STEM Challenges are great for helping kids develop critical thinking skills. And they are fun! This one is great for young kids around 5-6 years old. (Jewel is 5 years, 9 months here.) For older kids, you might want to add an extra element to the challenge such as, “Can you build a structure that can support a certain weight?” or “Can you build one that is taller than you?”

STEM Challenge: Can you build a 3D structure?

Paper straws and pipe cleaners

This might not sound like the hardest challenge ever, but it was just at the right level for Jewel. We talked about what 3D means (and I discovered she had a few gaps in her understanding). We chatted about various 3D shapes that she knew, and their relation to 2D shapes. We drew a picture of a square, and compared it to one of her cube shaped blocks. Likewise, we looked at a Jenga piece, and noticed that the sides were rectangles, but the whole piece was a rectangular prism. We talked about circles, and how a ball is actually a sphere.

We speculated which shapes might be easier or harder to build using pipe-cleaners and straws.

We talked about what the scissors might be for, and worked out that we could cut the straws and pipe-cleaners in halves or thirds, to make shorter sides if needed. And then I took a mental step back, and waited to see what she would come up with.

(As a side note: I offered the choice of paper or plastic straws, but the paper straws worked much better. They are stronger, the colours pop more, and they don’t have the bendy bit on the end. Plus they’re better for the environment, so win/win/win!)

At first Jewel wanted to make a cylinder, which I silently applauded for its ambition. Seconds later, she changed her mind and decided to make “one of those shapes with triangles on the sides”. She was a bit taken aback when I wouldn’t tell her how.

“This is your challenge, so I can’t tell you how to do it. But you can make any 3D shape or structure you like. It might take a few tries to figure out how you’re going to do it, and you can change structures half way through. Why don’t you start trying, and see if something works.”

Making a 2D triangle shape

Jewel made a basic 2D triangle shape easily enough. She had to work out how to twist the ends together – the first few attempts kept coming undone. (All this threading and twisting is great for her fine motor skills.)

She ran into some difficulty when she was trying to add in the third dimension. How was she going to get the straws to stand up? This is where critical thinking comes in. After a few tries, she worked it out.

Making a 3D triangular pyramid

Low and behold, she made a triangular pyramid (a pyramid with all equilateral triangle sides) AND, it doubles as a hat! If you pull it down on your head far enough, with one of the corners (or vertices) facing forwards, it looks like a beak. (She may have pecked her sister a few times.)

A triangular pyramid hat

A little later that day (after I’d had a chance to look it up and refresh my memory), we had a little hands-on geometry lesson with our Geomag rods, looking at the difference between a triangular pyramid, a square pyramid and a triangular prism, and talked about what 3D means again. Jewel pointed out that her straw and pipe-cleaner structure wasn’t strictly a triangular pyramid, as one of her sides is actually a double side. (She does like her pedantics.) So we decided that she must have created a brand new shape, which we’ve called a Jewel pyramid. We decided that, since it was still a 3D structure, it totally qualifies for our challenge.

Making Geomag triangular pyramids

STEM Challenge. Can you build a 3D structure

This post is part of the 28 Days of Hands-On STEM Activities for Kids blog hop that’s running all this month. Head over for more fun STEM Challenges to try. Which one will you try first?

28 Days of Hands On STEM

And keep an eye out for next week’s mini-theme: Coding for Kids!

* This post contains affiliate link(s). An affiliate link means I may earn referral / advertising fees if you make a purchase through my link, without any extra cost to you. It helps to keep this little project afloat. Thank you for your support, I really appreciate it.

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  1. Emma

    How fun! I love that there’s no one right way to do this one – you can make anything you can think of! (And I love your colorful straws, lol!)

  2. Tom

    Great post. Btw – thanks. Now i know what STEM stands for.

  3. Joy B.

    Did you have the pipe cleaners already in the straws or did your daughter think of that?


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