Next time you drive under a bridge or overpass, look for a sign on the side with numbers on it. It will tell you the bridge’s height above the road in inches and feet. Why? So we don’t have what happened in this picture! This truck tried to drive under a bridge even though it was too tall to fit. So the truck got stuck, and had to be pulled out. One way is to let the air out of the tires so the truck sinks lower and can roll out slowly. So why do trucks get stuck? Maybe the trucks are taller than their drivers think? Maybe the driver just doesn’t believe the sign? Either way, this is a case where doing the math could save the day.
Wee ones: Which is taller in that picture, the car on the left or the truck on the right?
Little kids: The truck got stuck at 2:00 pm, If it didn’t get un-stuck until 2 hours later, when did the truck finally roll free? Bonus: If the truck is an 18-wheeler and you’ve let the air out of just 1 tire, how many tires do you have left to do?
Big kids: If the bridge height was 11 feet 11 inches and the truck was 1 inch taller, how tall was the truck? (Reminder if needed: How many inches are in 1 foot?) Bonus: If that truck had a 36-mile trip, and the distance it had traveled so far was only 1/2 of what it had left, how far had it driven so far?
Wee ones: The truck is taller.
Little kids: At 4:00 pm. Bonus: 17 wheels.
Big kids: 12 feet. Bonus: 12 miles. If the distance that’s left is double the distance traveled already, that’s the same as having 3 pieces all that length….and 36 divided by 3 is 12.
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.