In this hands-on STEM activity, participants are challenged to build the strongest structure possible as they develop their design thinking skills.
- Medium washers
- Miniature marshmallows
- Paper plates
- Round toothpicks
Preparation (An adult should handle each of the following steps)
- Prepare marshmallows ahead of time. Open the marshmallow bag, put marshmallows in an open container and allow them to sit uncovered for two days.
- Create one or two structures to use as examples for those participating in the activity. Place a marshmallow at each end of a toothpick. Add a second toothpick by sticking it into one marshmallow. Add a marshmallow at the end of this toothpick. Continue adding toothpicks and marshmallows, experimenting with different shapes to create various structure components (squares, triangles and rectangles).
- Provide containers of marshmallows and toothpicks for your child to use.
- Give a set amount of time for your child to use the marshmallows and toothpicks to create different towers with various shapes and sizes.
- Have your child test their structure. Place a paper plate at the very top of each one, then slowly add metal washers on the plate until the structure begins to buckle.
- Keep a running count of the number of washers each structure can hold.
- Point out the different shapes your child used in their structures. Ask them why they used the shapes they did and if they think one is stronger than another.
- Explain that the triangle is the strongest building shape because it evenly distributes weight. It is used in the construction of bridges, roofs and buildings.
Educators: Use this activity in the classroom with these modifications
Divide your class into construction teams and have them work together to first design and then build different types of towers. Incentivize your students by creating different categories (tallest tower, strongest tower, tower with only ten marshmallows, etc.) and seeing which team can build the strongest version within these parameters. Give each team the opportunity to revise their building based on how it performs during the stress test. By adapting to each new situation, your students are developing valuable creative problem solving and design thinking skills!
What are we learning?
Any structure – from spider webs to bridges to tall buildings – must be strong in both tension and compression. Tension refers to the pulling or stretching of materials. As more and more materials are added to elongate a structure, these materials must stretch without breaking – much like a rubber band. Compressions refer to the pushing force that occurs when weight is added to a structure. For example, if you sit on a marshmallow, it will compress. Materials used for building must have the ability to hold weight as they are added to the structure.