⚙️ Gears & Ratios
When two gears mesh, the small one spins fast and the big one spins slow — and they always turn opposite ways. Change the teeth and watch the ratio. This is how bikes, clocks, and car engines work. Twice the teeth = half the speed.
Gear ratio = teeth of B ÷ teeth of A. It tells you how many times A spins for one turn of B.