What are Gears?

GEARS are wheels with teeth (cogs) that fit together and turn.

Examples of machines that use gears: hand egg beater, bicycle, watch

Vocabulary: machines, wheels, gears, teeth, cogs

Activity 1

Materials

Directions

Call on 2 students to have a race to see who can make the most bubbles.
Both students are given a bowl of liquid dish soap.
One student is given a spoon and the other student is given an egg beater.
Have each student put their tool/machine in the soap and try to make bubbles.
After approximately 1 minute the students should stop and examine both bowls to see who made more bubbles.
Ask the students to explain why the student with the egg beater won (made more bubbles).

Explanation

The egg beater has gears to help the beaters spin faster. The gears made the work easier.

small and large gears

Activity 2

Have students work together to brainstorm and list other machines that use gears.
Have students sketch/illustrate a machine/machines that use gears.
Students could also look in magazines, catalogs, or online for pictures of machines with gears.
Students could create a poster of Wheel and Gears or just Gears. (I love Sear's catalogs for this activity and even Home Depot or Loews catalogs or flyers are usually helpful. A catalog from a hardware store is also useful.)

Activity 3

If available give students some actual gears to manipulate and experiment with. Give them time to experiment then discuss their observations about gears. Ask questions about their observation time with the gears. Do the gears always turn in the same direction? Etc.
Younger students could trace the gears and draw arrows to show the direction of movement. Older students could sketch/draw the gears and label the direction(s) of movement.