Unit rates are great for making comparisons between certain things. For example if I was at a grocery store and I wanted to buy steak and I saw 10 ounces for $18 and 12 ounces for $22, I could determine which is a better buy and how much I am saving.
Let me show another example.
70 students in 5 classes = ___ students per class
"Per class" means in one class so we can rewrite the given statement using fractions.
![(70-students)/(5-classes) =(X -students)/(1-class)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b38luy93wo4efq9ah1h3pycu14hyhm1gp0.png)
To find out what goes in the blank, notice that we have a 1 in the denominator of our second fraction so we want to find a fraction that is equivalent to 70/5 that has a 1 in the denominator.
If we divide the numerator and the denominator of 70/5 by 5, we get the equivalent fraction 14/1 or
.
This means that the unit rate for 70 students in 5 classes is 14 students per class.
Unit rates can also be useful for solving the types of problems that I showed above.