Inside: This math activity with an index card is a mind-tickling science experiment that requires no-prep and will have your kids talking for days.
I’m super excited to be sharing this paper math science activity with you. It’s one of those low-key projects that doesn’t require any prep but engages your kids’ minds with science.
All you need is index cards and scissors.
Everyday objects offer plenty of opportunities to practice problem-solving and thinking like a scientist.
What we are trying to find out here is: can we, through only a skillful placement of cuts in an index card, make enough of an opening for a person to step through? And without breaking the card?!
Seems impossible, right?
This is on par with the question – Can a mice family make it past our perky cat and very alert German Sheppard (superb rat killer), and not only make it inside but actually make a cozy nest inside a bookcase cabinet?
Sounds not very likely, right? But you’ve probably already guessed that I wouldn’t be asking this question if the answer wasn’t yes.
In fact, we just had the exterminators over today (two of my kids are still in tears because they think the mice are cute, and we should have kept them as pets. Over my dead body, said I).
Now let me show you how you can use scissors to make an index card as big as it needs to be for your body to slip through it.
Magic Paper Math Science with Index Cards
What you need
Index cards (a couple for each kid)
Scissors (would be nice if you had one pair for each kid to prevent, he-is-breathing-on-my-neck type of interaction)
What to do
1. Start by giving each of your children a regular index card and ask:
Can you squeeze your entire body through an index card?
Most kids say, no way! It’s not possible!
2. Invite them to share what they know about paper.
What is paper made of? What properties does it have? Is it stretchy? Bendy? Heavy? Flexible?
If you’ve done other paper experiments in the past, like soaking paper in water, you can remind kids that paper expands in water, which helps to stretch it out in some cases. But since we are not using water today, we have to come up with another way to stretch paper.
3. Hand them scissors.
Can the paper be cut in such a way as to allow you to step through it?
They might need more than one index card to experiment! Remind them to keep the borders of the index cards intact. The opening is on the inside of the card.
4. When kids give up, be ready for demonstration.
Warning: the result is very dramatic and looks just like magic, especially when you memorize the cutting sequence and can do it smoothly. So take advantage of this opportunity to be a super-cool parent!). We made you a video (below) if you prefer visual learning.
Here it goes:
- Fold the index card in half the long way.
- Cut a rectangle out on the inside.
- Pay attention now because it makes a huge difference! We’re now going to make a series of cuts. The important thing is to start and end on the inside edges of the opening. See the photo.
- We’re alternating cutting on the inside and on the outside. You decide how close your cuts are. The higher the number, the bigger the opening. For my adult size, I had to make 19 cuts. Make sure it’s an odd number of cuts!
5. Unfold the index card slowly.
Be gentle here because the thin strips of paper might get tangled up, and you don’t want to tear it.
Gently stretch it out!
Our index card could stretch 24 inches!!!
6. Now it’s time for the test.
Can you really step through the paper without tearing it?
As you can see in the video, we had no problem getting through the paper. Not only my kids, but even I easily squeezed through the standard index card!
It was a hugely successful activity all around! My kids still jump up and down from excitement no matter how many times we’ve done it.
We used the standard index cards, which are 3×5. However, if your kids have trouble stepping through the index card, you might want to pick the next size up, which is 5×8 index cards.
Are you ready for more fun with paper?