Gumdrop Structures Engineering Challenge

Gumdrop Structures Engineering Challenge

This is an engineering challenge idea that I’ve modified from one I found on Teacher’s Domain. My 5-year old son was up for the challenge, and I’ve also done the activity with science teachers at a professional development workshop. You’ll love this activity as part of an engineering unit, when you’re introducing shapes, or just for a fun Friday or rainy day activity. Its up to you what parameters you put on the students. The more parameters, the more difficult the challenge. Want to make it even more challenging? Add a time limit, how high the book has to be off the table, or assign material “costs.”

In my descriptions below, I offer varying degrees of inquiry. My site has a through descriptions of what inquiry is and what it is not.

The Challenge: 
Using 10 gumdrops and 20 toothpicks, design a structure that can hold the weight of a large textbook.

STEM Connections
Science & math = physics & shape comparison
Engineering & technology = load distribution & building structures


The Big Ideas
Triangles are strong.
Large bases support more weight.

Materials: For each student (or pair of students):

  • 10 gumdrops
  • 20 toothpicks
  • 1 ruler
  • Disposable surface on which to work; small paper plate, or paper towels (optional, but sugar from the gumdrops gets a little messy.)

Inquiry Leveling Options

Provide students with step-by-step directions on how to build a gumdrop structure. (Like the“Gumdrop Dome” from Teacher’s Domain)

Low-Level Inquiry
Introduce the importance of shapes when building structures
Have students predict which shape they think will do the best

Mid-Level Inquiry
Introduce the challenge, explain how the houses will be tested (show the book), and then have them begin. No additional talk or help! Failure is an option! Encourage students to rebuild.

Construction Time!

Questions that provide hints/guidance during the building process: (Use at your discretion)

  • How will your roof affect the home’s ability to be tested?
  • How could you strengthen the joints?
  • Since you found that one triangle is good, would two be even better?
  • How could you broaden the base to give the house more support?
  • How does the number of toothpicks stuck into one gumdrop affect the strength of the joint?
  • It looks like the length of a toothpick limits you. Is a solution to that problem worth exploring?

You Decide: It is up to you whether or not you want to provide replacements for broken toothpicks or gumdrops that have been speared too many times. When students know they have limited resources, they may plan a bit more before beginning to build.

Lab Notebook: When ever possible, have students record the process of what they are doing and learning in a lab notebook. Encourage them to draw sketches, take measurements, and describe what happens during their testing sessions. If digital cameras and/or video cameras are available, use these to help record the process.

Testing Time!

Gumdrop Structure Testing 1

Encourage collaboration and celebrate failure.  Consider having students listing their attempts and failures on the board so everyone can learn from one another.

Gumdrop Structure Testing 2

Free Handouts

I have posted free handouts for this activity in my Teachers Pay Teachers store. Included in this file are two 2 student handouts; one for lower elementary that is low-level inquiry and one for upper elementary that is mid-level inquiry. Also included in this file is a thourough teacher’s guide with much of the same information I shared with you here.

Gumdrop Structure Challenge Teacher Lesson Plans


Gumdrop Structure Challenge Teacher Lesson Plans 2


A big thank-you to Marci for letting me guest post at Homeschool Scientist!

Darci the STEM Mom

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  1. 4


    Okay Marci, you need to pray for us we are trying this project today and my science abilities aren’t much better then my knowledge of Illinois Geography. 😉 And the Lord has given me a couple Math/Science kids! :O


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