topic badge
Grade 9

Ball Bounce (Investigation)



  • To experiment with collecting data.
  • To understand why collecting different types of data is useful for answering certain questions.
  • To practice with choosing their own graph type and analyzing spread data.

Pre-Experiment Questions

  1. How many times can you bounce a ball in 30 seconds?  Design an experiment to answer this question.
  2. What kind of data will you need to collect to answer this question? Why?
  3. What factors could affect the amount of times you are able to bounce the ball? Brainstorm at least 3. Remember to account for these when designing your experiment.

Possible Materials

  • Stopwatch
  • Tennis Ball or Rubber Ball
  • Pencil 


  1.  Gather the materials you need (a bouncy ball, a stopwatch, etc.). You can do this on your own or in a small group.
  2. Bounce the ball for the length of time your experiment requires. The amount of bounces should be recorded for each trial.

Post- Experiment Questions

  1. What graph do you think will best represent your data (dot plot, bar graph, bar graph, or histogram)? Why? Graph your data using your choice.
  2. What are the mean, median, mode and range for your data?
  3. Based on your calculations and your graph what would be the best measure of center for the amount of time you bounced the ball? Why?
  4. If you wanted to bounce the ball 1,000 times how long would it take you? If you worked in a group only look at your personal bounce data here.


Compare with friends! Have a friend (or another small group) complete the investigation as well, and hang up the the final graphs next to one another. Compare and contrast the graphs.

  1. Which person (or group) had the highest average number of bounces? How do you know?
  2. What can you say about the range of each of the graphs? How do you know?
  3. What center of spread would be appropriate for each graph? Does it vary from person to  person? Why?
  4. How do the different types of graphs used display the data in different ways? Does it affect the way you read the data?



Design and carry out an investigation or experiment involving relationships between two variables, including the collection and organization of data, using appropriate methods, equipment, and/or technology (e.g., surveying; using measuring tools, scientific probes, the Internet) and techniques (e.g., making tables, drawing graphs)

What is Mathspace

About Mathspace