Choose the sheet for the learner's age. Each prints on a single page. Build the project first, then fill it in together.
Ages 5-7: Draw & tell
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · Balancing Toys · Ages 5-7
My Balancing Butterfly
Balance your butterfly and watch what it does.
1. Draw your butterfly. Draw a circle where each washer is.
2. Where does your butterfly balance?
◯ On its head◯ On its tail◯ On one wing
3. Tap a wing. What happens?
◯ It falls off◯ It rocks and comes back
4. Draw another place where your butterfly balanced.
5. What helps it balance on its head?
Ages 8-10: Predict, test & record
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · Balancing Toys · Ages 8-10
Balance Test
Predict what your butterfly will do, then test it and record what happens.
1. Predict: if you tap one wing, the butterfly will...
◯ fall off◯ swing back and settle◯ spin around
2. Test it 4 ways: tap a wing; tape a coin on the tail; tape a coin on one wingtip only; balance it on a pencil eraser.
Try
What I did
Balanced on its head? (yes/no)
What happened
3. Look from the side. The washers are...
◯ higher than my fingertip◯ lower than my fingertip◯ level with my fingertip
4. What did you find out?
5. Why do you think the washers help the butterfly balance on its head?
Ages 11-14: Explain & design your own test
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · Balancing Toys · Ages 11-14
Explaining Center of Gravity
Use the idea of center of gravity to explain your butterfly and test it fairly.
1. Use the term center of gravity to explain why the butterfly can balance on its head.
2. Explain why the butterfly swings back after you tap it instead of falling off.
3. Bruce balances a hammer on a bar, and also hangs it from a string. Your butterfly is most like...
◯ the hammer on the bar (support under the center of gravity)◯ the hammer on the string (center of gravity at or below the support)
4. Question: does the position of an extra coin change how well the butterfly balances? Name what you will change, what you will observe, and what you will keep the same.
5. Run your fair test. Tape the same coin in a different spot each time.
Where I put the coin
What I kept the same
What happened (balanced, tilted, fell)
6. Where else: name another toy or object that stays balanced because its weight hangs low.
Answer guide for grown-ups
Homemade Science with Bruce Yeany · Balancing Toys · Answer guide
Answer guide
Ages 5-7: My Balancing Butterfly
Open answer: look for effort and careful observation.
On its head
It rocks and comes back
Open answer: look for effort and careful observation.
The washers (the weights on the wings)
Ages 8-10: Balance Test
Any prediction is fine; it should swing back and settle.
Open answer: look for effort and careful observation.
Usually a little lower than the fingertip (because the wingtips are bent down).
It balances on its head when the extra weight is at the front wingtips. A coin on the tail makes it tip backward; a coin on one wingtip makes it tilt toward that wing.
They add weight at the front, which moves the balance spot (center of gravity) forward to the head.
Ages 11-14: Explaining Center of Gravity
The washers move the center of gravity forward until it is right at the head, so the fingertip supports it directly under its center of gravity.
The center of gravity is at or below the support. A tilt lifts the washers (the center of gravity) up, and gravity pulls them back down, so it swings back to level.
The hammer on the string (center of gravity at or below the support)
Change: where the coin is taped. Observe: whether it balances, tilts or falls. Keep the same: same coin, same butterfly, same support, same gentle placement.
Look for: only the coin position changes between trials; coin near the tail tips it back, near the front wingtips keeps it balanced.
Examples on this page: the balancing eagle toy, the tweety bopper, the balancing pencils, the wire animals.