Guessing Gumballs

How many gumballs are needed to fill the jar?

Ontario Grade Levels:
Common Core Grade Levels:

Shared By:
Kyle Pearce

Math Topic:
3D Measurement: Volume of a Cylinder, Volume of a Sphere and Proportional Reasoning.

Ontario Curriculum Alignment:

Common Core State Standard Alignment:

Guessing Gumballs 3 Act Math Task Resources

Grab all the videos/images by clicking download below:

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Real World Applications of 3D Measurement

Proportional Reasoning With Volume of a Cylinder and Sphere

Guessing Gumballs 3 Act Math Task

In this 3 act math task, students sharpen their proportional reasoning and 3D-measurement skills as they try to determine how many packages of gumballs as well as how many gumballs (individually) will it take to fill the cylindrical jar. The learning goals for this task include:

  • calculating the volume of a cylinder and applying their knowledge;
  • calculating the volume of a sphere and applying their knowledge;
  • applying their knowledge of proportional reasoning to solve problems.

Act 1, Scene 1: Introduce The Problem

Show students the following video or this photo:

Ask students to talk to a neighbour and come up with some possible questions.

This task will focus on two questions:

Q1 – How many packages of gumballs will it take to fill the jar?

Q2 – How many gum balls (individually) will it take to fill the jar?

You might want to show the students the following video before or maybe even after they discuss with a partner and make a prediction:

Act 2 – Give Students Some Information

After students make a prediction, have them discuss with their partner what information they need to make a more accurate prediction.

Then, show this video clip or show these photos:

Guessing Gumballs Act 2 Gumball Diameter

Guessing Gumballs - Act 2 - Jar Height

Guessing Gumballs Act 2 Jar Height

At this point, students should be able to improve their prediction of how many individual gumballs it would take to fill the jar by calculating the volume of the jar and volume of a gumball.

You can also challenge them by telling them how many gumballs on average are in each package:

Guessing Gumballs - Act 2 - Number of Gumballs Per Package

Act 3 – Reveal the Solution

Once students have shared out their work, updated their predictions based on their calculations and some good ‘ol debating happens in your classroom, show them these two clips:

Knowledgehook Gameshow

Check out the matching Knowledgehook Gameshow:

Make a clone of the Gameshow so you can edit to your liking here.

Clone Gameshow


Just added some more resources including a Keynote Slide Deck fully loaded and ready to rock in your classroom!

How’d It Go?

If you use this task in your classroom, please share your experiences in the comments section! Always appreciative of any improvements that can be made including resources you might want to share for inclusion.

Download Resources For This Math Task

Click on the button below to grab all the media files for use in your own classroom:

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