Cardboard Engineering Challenge
Child designs and builds a working cardboard mechanism (catapult, marble run) and improves it through tests.
- Age8 to 12 years
- TimeAn hour or more
- EnergyModerate
- CostFree
- WhereIndoors
- Prep5 min
Your child designs and builds a working contraption out of cardboard, such as a small catapult or a marble run, then tests it and improves the design.
How to do it
- Agree on what the contraption should do, such as flinging a pom-pom or rolling a marble from top to bottom.
- Have your child sketch a rough plan and gather the cardboard and bits they will need.
- They cut and join the pieces with tape or glue to build a first version, with an adult handling any tricky cuts.
- Test it and watch what happens, then ask your child what one change might make it work better.
- Make that one change, test again, and repeat, keeping the versions so they can see the progress.
What you need
- Cardboard
- Tape
- Glue stick
- Scissors
- Rubber bands
- Launch object
Signs it is working
Your child sketches or describes a plan before building. They test the build and name a specific change rather than rebuilding at random. A later version works better than the first at the agreed task
If it is not quite clicking
The build keeps collapsing: Help reinforce joints with extra tape or a cardboard brace rather than starting over. Child is frustrated that version one does not work: Remind them that testing and changing is the whole point, and celebrate the first small improvement. Cutting thick cardboard is too hard or risky: The adult does those cuts while the child directs where
Make it yours
Younger (6 to 8 years): Build a simple ramp or chute with the adult doing most cutting and the child taping and testing. Older (10 to 12 years): Add a measurable target, such as launching furthest or the fastest marble time, and log each version's result. Siblings: Each builds their own and they compare, or they build one larger contraption together
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