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Mathletics-Inspired DIY

DIY Balance Structure

Mathletics Blog Post (1)


Create a delicate balanced structure to learn about how weight and the location of weight affect the way things balance or don’t balance! Adult supervision is required.


-1 Cork

-2 Barbecue skewers

-1 Toothpick

-2 Marshmallows


Step 1: Try balancing the cork on just one finger. It’s hard, isn’t it? That’s because the center of gravity is right in the middle of the cork.

Step 2: We are going to make balancing the cork much easier by lowering its center of gravity. Take the two barbecue skewers insert them into each side of the cork making sure they are inserted at the same level.


The structure should look like this now. You can try balancing it and it is still difficult to do.

2 skewers in cork

Step 3: Add a marshmallow to the end of each barbecue skewer.


Here's what your structure should look like now that you've added marshmallows at the ends.

marshmallows on end

Try balancing it now. Easier, right?

Step 4: Insert a toothpick into the bottom of the cork, right in the center and try balancing the toothpick on the tip of your finger. Wow, it works!


Try balancing it on different objects. Impress your friends by balancing it on your head!

But...why does this happen?

All objects, regardless of their size or shape, have a center of gravity. The lower their center of gravity is, the lower their risk of getting toppled over.

Think about race cars. Have you ever noticed how they are designed so low to the ground? They’re designed that way because it puts their center of gravity lower and keeps them from tipping over when they’re going at high speeds around the race track.

The same thing is happening with your experiment. As you add more and more weight below the cork, you are also lowering the cork's center of gravity.

Continue exploring:

Add more items to your tree to make it larger and more complex. Remember that both sides need to have the same items and need to be below the cork in order for the structure to keep balance.

Learn more about how math can be seen all around us at Mathletics, our new summer exhibit. More information is available at

Posted by Miranda Clark at 10:58 PM
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