Math in Real Life: Figuring Gas Mileage

Another real life math skill that your child will need to know someday is the ability to figure out gas mileage. Most of us think about the gas mileage a car gets before purchasing a new car, and being able to estimate how much gas will cost can help when planning a budget for a road trip.

Introducing Gas Mileage

Most children will not have any idea what gas mileage is when you say those words to them. Therefore, you will need to start by explaining that gas mileage is how many miles your car can travel on one gallon of gasoline. It can also by called mpg or miles per gallon.

Next you will need to teach them how to find a car’s mpg. Explain that you can take the number of miles that a car drove from one gas stop to the next and divide that number by the gallons of gas it took to fill up the tank. You may want to give your child some examples to solve before they do any real life solving.

Track the Gas Mileage of Your Car

Have your child keep a small notebook and pencil in the car. Every time you stop for gas, let your child record the odometer number and how many gallons of gas you filled up the tank with. Then on the way home from the gas station, have them use those numbers to figure out the mpg for that fill up. They will have to take the following steps:

  • Subtract the last odometer mileage from the mileage that you just wrote down. This will give you the amount of miles you have traveled since the last gas station stop.
  • Divide that answer by the number of gallons you put into your tank. (Remember though that you have to fill the tank up for this to work correctly.)
  • You may want to have them round their answer to the nearest tenth each time they find the gas mileage.

Find the Average Gas Mileage

Once you have tracked your gas mileage several times, you can use those mileages to find your car’s average mpg.  Simply add up all your gas mileages and divide that answer by the number of times you found the gas mileage to get an average.

Find the Cost of Gas for a Long Trip

To take this real life exercise a bit further, you can have your child use your average gas mileage to figure out how many gallons of gas you will use to get from one point to another. Have your child use a map to learn how many miles it is from their starting point to their destination. Then they should divide that total number of miles by the average mpg of your car. This equation will tell your child how many gallons of gas it will take to complete their trip.  You could then have them use an average cost of gas for the country or state to figure out how much it would cost to drive that trip. Have them multiply the number of gallons the trip would take by the average cost of gas to come up with the final amount.

Learning how to track a car’s gas mileage or plan the cost for a big trip is an important skill that children should be able to do as adults. Plus it’s a fun hands-on way to review some of the math concepts you are covering like multiplying, dividing, averaging, and working with money. What other real life examples do you use with your children?

Photo by: Marlon E

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