Which ball bounces the most times?
- 🧍 Drop from standing: never climb
My hypothesis
If I change the kind of ball, then how many times it bounces before it rolls will ______, because ______.
You fill in the blanks. Think about which ball feels the most squishy, and which one springs back hardest when you squeeze it. A guess is a good because: the test finds out.
Change, measure, keep the same
CHANGE
the kind of ball: Tennis ball, Rubber ball, Foam ball
MEASURE
how many times it bounces before it rolls, in bounces
KEEP THE SAME
- dropping it from the same height
- the same hard floor
- letting go, never throwing
Scientists call the thing you change the independent variable and the thing you measure the dependent variable. The things you keep the same are the controls: if one of them changed too, you wouldn't know which change made the difference. Try each of the 3 levels 3 times.
What you need
- Four different balls: tennis, rubber, foam and ping-pong: a tennis ball, a rubber ball and a foam ball
- Crayons or markers
- Paper
Steps
- Stand on a hard floor and hold the tennis ball up as high as your nose.
- Let go. Don't throw it, just open your hand.
- Count every bounce out loud until it rolls away.
- Your grown-up writes the number down. Do it two more times.
- Now do three drops with the rubber ball, and three with the foam ball.
- Colour one box for each bounce. Which ball has the tallest stack?
Every step is one you can do yourself, with a grown-up nearby. Write each number down straight away, in the table below, so nothing is lost.
Your results table
Name ______________________ Fair day ____________
Question: Which ball bounces the most times?
I changed: Ball I measured: how many times it bounces before it rolls (bounces)
| Ball | Try 1 (bounces) | Try 2 (bounces) | Try 3 (bounces) |
|---|---|---|---|
| Tennis ball | |||
| Rubber ball | |||
| Foam ball |
MY GRAPH (a bar graph: ball along the bottom, bounces up the side)
What I noticed: ______________________________________________
Write each try's number in its box. Then draw a bar graph, one bar for each thing you tried.
Name ______________________ Fair day ____________
Question: Which ball bounces the most times?
If I change the kind of ball, then how many times it bounces before it rolls will ________________, because _____________________________________________
| I CHANGE | I MEASURE | I KEEP THE SAME |
|---|---|---|
| Ball: Tennis ball, Rubber ball, Foam ball | how many times it bounces before it rolls (bounces) |
|
What I think will happen, in my own words:
Name ______________________ Fair day ____________
Question: Which ball bounces the most times?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which ball bounces the most times?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which ball bounces the most times?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which ball bounces the most times?
My hypothesis was ☐ right ☐ partly right ☐ not right.
I know because my numbers show:
What surprised me, or what might have gone wrong (7th and up):
Next time I would test:
Idea: Change a second thing: drop each ball on carpet as well as the hard floor, and count the bounces on both.
Why it works
A bouncy ball squashes when it hits the floor and then springs back, and the spring pushes it up again. A foam ball soaks up the bump instead of springing back, so it stops sooner.
Going further (7th and up): Change a second thing: drop each ball on carpet as well as the hard floor, and count the bounces on both.
My picture board
A kindergarten board is one page: the question, a guess to tick, a drawing of the test, a box coloured for each count, and what your child found out, in their words. Glue it to a folded card, or the middle of a tri-fold.
Which ball bounces the most times?
I think… tick one:
- ☐ Tennis ball
- ☐ Rubber ball
- ☐ Foam ball
This is my test: draw it.
I counted: colour one box for each bounce, for my first try.
I found out:
Board layout
- ❓ Question (10 × 8 in): Which ball bounces the most times?
- 💭 Hypothesis (10 × 9 in): If I change the kind of ball, then how many times it bounces before it rolls will ______, because ______.
- 🧺 Materials (10 × 12 in): 3 things: see your list.
- 🪜 Steps (22 × 9 in): 6 steps, three tries at each level.
- 📊 Results (22 × 16 in): Your table (Ball down the side, tries across) and your bar graph.
- ✅ Conclusion (10 × 14 in): My hypothesis was right / partly right / not right. I know because…
Materials to list: Four different balls: tennis, rubber, foam and ping-pong; Crayons or markers; Paper.
Bring photos or drawings of your test. Nothing wet, hot, powered or alive on the table.
This project at your grade
| Kindergarten | Tries: three at each level (one is fine at a first fair). The table: levels and tries, numbers or pictures. The graph: a picture, or a simple bar graph. The conclusion: what happened, in their words. |
|---|
From 4th grade up, the table gets a mean column. See every project for kindergarten, or print a blank results table.
What a judge will ask
- What did you change, and what did you measure? I changed the kind of ball and measured how many times it bounces before it rolls, in bounces.
- What did you keep the same, and why does that matter? I kept dropping it from the same height and the same hard floor the same, so the only difference was the kind of ball.
- How many times did you test it? 3 times at each of my 3 levels.
- If you did it again, what would you change or test next? I'd drop each ball on carpet as well as the hard floor, and count the bounces on both.
Make it yours
Keep this project on this device and Peabody counts down to your fair day, with a plan for each day. Nothing is sent anywhere.
Try next
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