Closed and open
Electricity needs a complete loop. When the metal washer touches the right tooth, it bridges the gap and the buzzer beeps. Lift the tool and the loop is open again.
Level 2 · Advance Leeuwenhoek · Ages 5–7
My Little Dentist
Can you find the hidden gap and make the buzzer beep?
One tooth has a hidden gap in its circuit. Use a dentist tool with a metal tip to touch the teeth. Find the right tooth and the loop is complete. BEEP!
What children make
- A printed face card with cut-out teeth
- A battery pack and a buzzer
- Wires and conductive tape on the back of the card
- A card dentist tool with a metal washer on the tip
What you discover
- Electricity is energy. It can make lights glow, motors spin and buzzers beep.
- A simple circuit needs a battery, a path and something to power.
- Conductive tape has metal in it, so electricity can flow through it.
- A closed circuit works. An open circuit has a gap, so it stops.
How it works
The science inside
Conductors
Metal lets electricity flow easily, so it is a conductor. Paper, plastic and rubber don't, so they are insulators.
Red and black wires
The red wire usually connects to the battery's positive (+) side. The black wire usually connects to the negative (−) side.
Interactive exhibit
Try it: find the hidden gap
Find the hidden gap
Tap the teeth with the dentist tool. One of them has the hidden gap. Can you find it?
S.A.M.'s safety tip
Only the teacher uses the hot glue gun. Tell your teacher if a battery looks damaged, leaks or feels hot.
Watch before you build
Glue Gun Safety with S.A.M.
Tools and workshop skills · 1:19
Glue Gun Safety with S.A.M.
Before using a hot glue gun, learn how to keep your hands safe and why asking your teacher matters.
- Always ask your teacher first
- Never touch the hot metal tip or fresh glue
- Put the glue gun back on its stand when you finish
Enquiries
Want to build this too?
Come and see what your child could build. Classes run in Rochedale, on Brisbane's southside. Send us a message and we'll help you find the right level.
