Ages 4-7 · child and adult
Periscope: see over an obstacle
Build a cardboard periscope with two shatterproof mirrors. Use it to find a secret symbol behind a box.
Set your own pace. Preparation depends on your materials.
What to gather
- Long narrow box or cardboard
- Two matching acrylic mirrors, about 5 × 5 cm
- Tape, ruler and pencil
- Adult scissors and a picture card
Keeping it safe Use only acrylic mirrors with covered edges. An adult cuts the cardboard. Never look at the sun or a bright light.
Choose a challenge level
Ages 4-5
The adult builds the tube; the child chooses and finds symbols.Ages 6-7
Draw the light path through both mirrors. Move just one mirror, then restore the view.Step-by-step instructions
An adult makes a tube about 25 cm tall, 5 cm wide and 3.5 cm deep inside, for 5 × 5 cm mirrors. Cut a top-front and bottom-back window; leave one side open.
The adult cuts cardboard right-triangle supports with two perpendicular 3.5 cm sides. Tape the mirrors along their sloping edges behind the windows. Keep the mirrors parallel at about 45°, reflective faces pointing inward towards each other.
Look through the lower window. The adult adjusts the mirrors until you see a card in front of the upper window. Secure them and close the side.
TATAAA
Now turn it into a game
Secret observer: hide one of three cards behind a box. Identify it through the periscope without peeking over. Swap roles and choose a new hiding place.
When it gets tricky
A dark view? Check the reflective faces point towards each other and tape is not covering the windows.
When an experiment goes wrongWhen you are done
You can identify the hidden picture through the lower window.
If your child does not want to continue, it is fine to stop. You can safely swap roles or adapt the rules.
What to notice
Light reflects from the upper mirror to the lower one, then into your eye. Each mirror changes its direction.
Background reading
Keep exploring
Head out on an adventureA treasure map without reading
Three pictures can lead to treasure. Your child makes a map and the adult tries following it.
Open mission
Build and testShadow theatre: who is hiding?
Tell a story with hands and a torch. Discover how to turn a small shadow into a giant.
Open mission