Submarine Cardboard Dual-Mirror Periscope Sight System

40 mins Ages 6-11 Indoor

An engaging, screen-free learning activity that builds real-world creativity and critical thinking for kids aged 6 to 11.

Materials Needed

  • • Tall rectangular cardboard tube or clean 1L milk cartons (1–2 units)
  • • Small flat glass or acrylic pocket mirrors (approx. 5x7 cm) (2 units)
  • • Heavy duct tape or painter’s tape (1 roll)
  • • Ruler and protractor (1 set)
  • • Utility scissors or craft knife (1 unit)

Pro Tips

  • → Cut two parallel 45-degree angled slots at opposite ends of a long rectangular cardboard tube.
  • → Slide two flat mirrors into the slots facing each other: the top mirror captures light from above, bouncing it down to the lower mirror.
  • → Crouch behind a couch or doorway and raise the periscope to scout secret rooms without being seen.

Safety First

Adult assists with cutting mirror insertion slots into rigid cardboard.

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Step-by-Step Instructions

1

Step 1

Mark two 45-degree angled slit lines on opposite sides at the top and bottom of a tall cardboard carton.

2

Step 2

Carefully slice the slits and insert two flat pocket mirrors facing each other in parallel alignment.

3

Step 3

Cut viewing peepholes in the cardboard directly opposite each reflective mirror surface.

4

Step 4

Tape mirror edges secure, duck behind a low couch, and look through the lower peephole to scout the room above.

What they are learning

Dual planar mirror reflection optics 45-degree angle of incidence alignment Submarine navigational periscope engineering