Gears are wheels with teeth around the edge. When their teeth lock together, one gear can push the next gear to spin!
Watch them spin! Tap Next to find out their secret. 👉
Gear teeth fit into the gaps between the next gear's teeth. They mesh — like fingers from two hands locking together. That grip is what lets one gear turn another.
Here's a cool rule: when two gears mesh, they turn in opposite directions. If the left gear turns clockwise (the way a clock's hands move), the right gear must turn anti-clockwise.
The blue-purple gear on the right will turn…?
A small gear has fewer teeth, so it has to spin fast to keep up with a big gear. The big gear turns slowly, the small one spins quickly. Drag the slider and watch!
Notice the small gear's line whizzes around far more times. That's a gear ratio!
Gears let us trade one thing for another. Match each job to the right gear setup. Tap your answer!
🚴 A bicycle going up a steep hill — you want extra pushing power so it's not too hard to pedal.
🏎️ A race car on a flat track — you want lots of speed.
Line up three gears so all their teeth touch, and turning one gear turns them ALL. Tap the empty space to drop in the missing gear and connect the chain.
Did you notice? Gear 1 and gear 3 spin the same way, because gear 2 in the middle flips the direction twice!
Gears are hiding everywhere! Tap each card to guess what's inside.
You now know how gears work together:
Next time you spot a clock or a bicycle, you'll know there are clever gears working together inside! ⚙️✨
Great work, young engineer. 🌟