Guide

12 : 36
12 : 60
36 / 12
60 / 12
3 / 1
5 / 1
Say “12 to 36 Gear Ratio”
Say “3 to 1 Gear Reduction”
Say “12 to 60 Gear Ratio”
Say “5 to 1 Gear Reduction”
Example 1
Example 2
Gear Reduction
Gear Reduction
Gear Ratio
Gear Ratio
G.3
cont.
Expressing Gear Ratio and Gear Reduction (Grades 4-8)
Both Gear Ratio and Gear Reduction are mathematical expressions that describe the relationship
between a Driving Gear and a Driven Gear. However, it’s important to understand the dierent
but similar ways they are expressed. Both use the number of teeth on each gear as key values,
although their order is reversed.
Gear Ratio is expressed this way:
(Driving Gear Teeth) : (Driven Gear Teeth)
Gear Reduction is expressed in reverse:
(Driven Gear Teeth) / (Driving Gear Teeth)
Note: Gear Reduction is seen as a fraction that is often reduced
to simplify the expression Driven Gear.
Driving
Gear
Driving
Gear
Driving
Gear
Driven
Gear
Driven
Gear
Driven
Gear