MAM Day 29: Are we there yet?

We've covered math on the T, and math on foot, but math in a car is one of the obvious places where you'll find math. The speedometer is a great start, it's measuring speed in miles per hour. We can use the speedometer and road signs to know how much further we've got to go. If we've been traveling at roughly 70 miles/hour or MPH, and we're 200 miles away from our destination, we should get there in roughly 3 more hours. Easy right?


What I've always wondered is why speedometers go so high, typical highway speeds don't go much higher than 75 mph.
The other big math process we use for cars is determining gas mileage. Gas mileage is how many miles your car can run per gallon of gas. Calculating gas mileage requires that you know how many gallons your car's gas tank holds, and also keeping track of the odometer. The odometer tracks how many miles your car has traveled in total. Newer cars have multiple odometers that can also track the miles on a single trip, very handy for tracking your gas mileage.


The odometers are the counters in the middle.
So if you wrote down the miles off the odometer when you fill up, and then write down the miles at your next fill up (your car should be as empty as possible to track accurate mileage). Find the difference in miles and you have the total miles traveled on that tank of gas. Divide the total miles by how many gallons of gas your car can hold and you've got gas mileage in miles per gallon. Here's an exercise for kids to calculate gas mileage.

Obviously, the higher your gas mileage, the better. Cars typically get better gas mileage on the highway because they aren't wasting gas for starting and stopping. Heavy traffic will cause your gas mileage, your wallet, and your sanity to suffer. My aunt suggested that I keep track of gas mileage to make sure the car is running well. If your gas mileage changes significantly, you'll know something's up and you should take your car to the shop. If you track gas mileage for a few months, you'll get a sense of how long an average tank of gas will last.


I love license plates!
There's tons of numbers on a road trip, from license plates to road signs, billboards to just counting other cars. A great resource for car math ideas.

A video of a mental math game in the car

Although I don't quite understand the sport of car racing (it's incredibly wasteful of gas and I'm not sure how much athleticism is really required for drivers and the spectators) there is a lot of math involved with car racing from car speeds, laps, times in comparison to other cars, and the prep work that's required before a race, tire treads, weight restrictions, and finally the all famous speed of pit crews.

Here's more complex car math including horsepower and torque and tire diameters and gear ratios. Everything else is car lingo I don't understand.

Happy road tripping!



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