How an odometer counts
Tap Drive 1 km and watch the ones wheel.
22 parts
Made of:
Did you know?
The cable turns a worm, the worm turns the ones wheel one tenth of a turn for each kilometer. As a wheel rolls from 9 to 0, its two carry teeth turn a small pinion a quarter turn, and the pinion moves the next wheel on by exactly one number.
How to play
- Tap Drive 1 km. The ones wheel turns one number.
- Drive until the ones wheel says 9. Then watch: 9 turns to 0 and two little teeth push the tens wheel on by one.
- Tap Jump to 0999 to see a large carry: three wheels turn at once.
- Tap any part, or use ◀ ▶, to zoom in and read what it does. Take it apart slides the pieces off along their axes.