A rate is a comparison of two quantities that have different units. An example is 90 miles/3 hours, which is read as 90 miles per 3 hours.
Unit rates are rates where the denominator is 1. An example is 30 miles/1 hour.
We will learn how to change a rate into a unit rate. In this example, we will change the rate, 250 miles/10 gallon, into a unit rate by dividing the numerator by the denominator. 250 ÷ 10 = 25, so the unit rate is 25 miles/gallon.
If you still seem confused, watch this video from YouTube for more information.