Gear Ratios

Gears are wheels with teeth that fit together to transfer motion, change speed, or change direction. By connecting large and small gears, you can build a gear train to explore how gears make work easier.

1. Print and color a gear pattern.
2. Tape the pattern to a Styrofoam tray and have an adult cut out the gears.
3. Pin the gears to a piece of cardboard so their teeth fit together.
4. Turn the big gear slowly and watch how the small gear moves.
5. Mark each gear with a colored dot at the top, then count how many turns each gear makes as you spin the big gear.
6. Optional: Add a small handle to the big gear to make it easier to turn.

📄 Learn about gears - Home Science Tools: https://learning-center.homesciencetools.com/article/learn-about-gears/

• Use ridged water bottle caps as simple gears.
• Try gears from building kits like LEGO or K’Nex.
• Experiment with three or more gears to build a gear train with idler gears.

• Have an adult cut the Styrofoam with a sharp knife.
• Handle thumbtacks or pins carefully to avoid injury.

• Why does the small gear turn faster than the big gear? (Because the smaller gear has fewer teeth, it makes more rotations per turn of the big gear.)
• Why do the gears turn in opposite directions? (Because the teeth push against each other in reverse.)
• How do gears make work easier? (They allow you to trade force for speed, or change the direction of motion.)