Compare quantities and find the rate per one unit.
A ratio is a comparison of two quantities by division. Ratios can be written three ways: as a fraction, with a colon, or with the word "to." A unit rate is a special ratio where the second quantity is 1. Unit rates make it easy to compare different situations.
Three Ways to Write a Ratio
Unit Rate
To find a unit rate, divide both quantities by the second quantity.
A car travels 240 miles in 4 hours. Unit rate = 240 ÷ 4 = 60 miles per hour. Now you can find any distance: 7 hours × 60 mph = 420 miles.
Remember This!
When comparing two deals (like price per ounce), convert both to unit rates before comparing. The smaller unit price is the better deal.
A store sells 5 notebooks for $7.50. What is the unit price per notebook?