you usually get four prices for four different gasoline's you can pump.
ex.
unleaded =3.89
unleaded plus =3.99
unleaded premium =4.55
diesel #2= 4.65
so unleaded gas is $3.89 per gallon of gas.
so if you got 5 gallons of gas it would be 5 times$3.89
![5 * 3.89](https://img.qammunity.org/2019/formulas/mathematics/middle-school/6y86dfd8tu9g32xtz43zmjo9w9caau6u6t.png)
these prices are just an example.