Students learn that a rate is a comparison of two measurements or amounts that have different units. For example, 60 miles in 2 hours is a rate. Students learn that a unit rate is a rate in which the second rate is 1 unit. For example, 30 miles in 1 hour, or 30 miles per hour, is a unit rate. In the problems in this lesson, students are given a rate, and are asked to find the corresponding unit rate. For example, if there are 70 students in 5 classes, find the number of students per class. To find the unit rate, divide the numerator and denominator of the given rate by the denominator of the given rate. So in this case, divide the numerator and denominator of 70/5 by 5, to get 14/1, or 14 students per class, which is the unit rate.