How many helium balloons lift a stuffed animal?

01What you need

• 8 to 12 helium latex balloons on ribbons, filled at the store the same dayAbout $15
• A small, light stuffed animalHave
• A box of paper clips and a paper cupHave
• A kitchen scale, if you have oneHave
• Paper and a pencil for the chartHave

Where: An indoor room with the doors and windows shut and the fan off, so drafts don't push the balloons around.

02Steps

1. Measure one balloon's pull

   TogetherTie one balloon's ribbon to the rim of a paper cup. Drop in paper clips one at a time until the cup stays sitting on the table. Write the number down: that's one balloon's lift, in clips.

2. Add balloons and graph

   KidTie on a second balloon and count clips again, then a third. Before each one, ask, "How many do you think it'll hold now?" After each, they put a dot on the chart: balloons along the bottom, clips up the side.

3. Weigh the passenger and predict

   TogetherWeigh the stuffed animal on the kitchen scale, then weigh the cup of clips one balloon held. Divide: if the animal weighs as much as five cups, predict about five balloons. They write the prediction in big numbers.

4. Test it

   KidTie the predicted number of ribbons around the animal's middle. Hold it over the carpet and let go. Does it rise, float or sit? Add or take off one balloon at a time until it just floats.

5. Compare and explain

   TogetherWrite the real answer next to the prediction. Ask, "Were we close? Why might it take more?" Ribbons and knots weigh something too.

6. Wrap up safely

   DadUntie the balloons from the animal. You deflate them over the trash can and throw them out with every piece, so nothing ends up outside or in a little one's mouth.

03If it stalls

• If counting clips one by one drags, drop them in five at a time, then go back one by one at the end.
• If the animal won't lift even with every balloon, try a lighter toy, like a finger puppet or a sock with eyes.
• If the balloons drift and tangle, shut the door and turn off any fans. Drafts push them around.
• If the numbers drop later in the day, that's real science: the balloons slowly lose helium. Redo step 1 and compare.

04Variations

05Sources

• Helium inhalation. The Missouri Poison Center says inhaling helium from balloons is not always safe and deaths have occurred, that helium can replace oxygen in the bloodstream and cause dizziness, fainting and falls, that a party balloon's helium may be dangerous to a young child, that inhaling straight from a tank is much more dangerous, and to call 911 if someone becomes unresponsive. Poison Help is 1-800-222-1222. Missouri Poison Center Checked Oct 15, 2026
• Balloons and suffocation. CPSC warns that children under 8 can choke or suffocate on uninflated or broken balloons, recommends that children under 8 not play with uninflated balloons without supervision, and says to collect the pieces of a broken balloon right away and throw them out of young children's reach. U.S. Consumer Product Safety Commission Checked Oct 15, 2026
• Balloons and choking, up to age 8. The AAP says balloons are among the small round objects that cause the most choking deaths and pose a choking risk to children up to 8 years of age. American Academy of Pediatrics (HealthyChildren.org) Checked Oct 15, 2026
• Don't release balloons. NOAA's Office of Response and Restoration says released balloons come back down, get snagged in trees and power lines or end up in waterways, that animals can eat balloon debris or get tangled in it, especially with ribbons attached, and asks people not to release balloons into the air. National Oceanic and Atmospheric Administration Checked Oct 15, 2026

Idea from a r/daddit thread on free and low-cost ideas, in our words. The facts come from the sources above.