Parents, Educators & Engineers

Harmless Holder

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The Invention Challenge

Invent a holder for six cans that's animal-safe, sturdy, convenient, and easy to carry.

Materials (per team)

  • 6 full cans of soda, seltzer, or juice
  • cardboard (approx. 8.5x11 in.)
  • copier paper
  • duct tape
  • wax paper
  • string
  • 4 paint stirrers
  • 6 rubber bands

Brainstorm and Design

To help you brainstorm, look at the materials, discuss the questions below, and sketch some design ideas.

  • The cans in a six-pack are all the same size and shape. Name some other containers that hold objects that are the same size and shape.
  • You need to be able to carry the cans easily. What are some different kinds of handles used to pick up objects?
  • How can you hold six cans together?
  • Should you arrange the cans on end? On their sides? Stack them?
  • How will you remove the cans easily?
  • How will you carry the holder?


What've you got so far? Think about how you are going to keep the cans from falling off. Any plans for using other materials?

Test, Evaluate, and Redesign

Okay, show us what you've got. NOTE: If your holder's bending and twisting, that's FORCE at work, pushing and pulling on the parts. You need to reinforce things to resist the force.

Discuss What Happened

To learn about an idea's strengths and weaknesses, inventors build a series of early designs called prototypes. How would you present, compare, and discuss the prototypes you built today?

  • Which features worked best for holding cans together? Picking them up? Carrying them?
  • Which design is sturdiest? Lightest? Simplest? Uses the fewest materials?
  • Your design had to withstand bending, twisting, and pushing. How well did you design resist these forces?
  • What are some ways an improved holder could help the environment?
  • If an animal were to eat some of the materials you used today, it might still cause problems. How are these problems similar to or different from the problems caused by plastic six-pack holders?