A license plate is that little metal rectangle that helps us keep track of cars: each car gets its own set of letters and numbers. Since license plates are made of aluminum, it’s much harder to break them than the plates in your kitchen. But one guy broke 23 of them – and he did it in 60 seconds! Bill Clark is a “strongman.” He does stunts to show what you can do if you lift weights to become super-strong. He rolls up frying pans, lifts cars, and yes, rips license plates right in half. To do this, Bill holds the metal rectangle against his belly, then pushes the top and bottom edges in opposite directions, and snap goes the license plate! The real question is, if Bill can do so much in just 1 minute, what can he break in an hour?
Wee ones: If a license plate has 3 letters and 4 numbers, does it have more letters or numbers?
Little kids: If Bill breaks his own record of 23 by 1 more license plate, how many doe he break? Bonus: How many pieces does he make if he snaps 8 license plates in half?
Big kids: Say Bill can’t keep up the record pace, and snaps “only” 20 license plates in the 2nd minute, 17 in the 3rd minute, 14 in the 4th minute… what’s the pattern, and how many do you think he snaps in the 7th minute? Bonus: If Bill had snapped 1 license plate every 3 seconds for 1 minute, would he have set the record at 23 plates?
The sky’s the limit: If Bill can keep breaking 23 plates per minute, how long would it take him to break more than 1,000 plates?
Wee ones: There are more numbers, because 4 is more than 3.
Little kids: 24 license plates. Bonus: 16 pieces, because each snapped plate makes 2 pieces, and 8 x 2 = 16.
Big kids: Bill snaps 3 fewer plates in each minute, so he’d snap 11 in the 5th minute, 8 in the 6th minute, and 5 in the 7th minute. Bonus: No, he would’ve only snapped 20 plates, because 60 divided by 3 equals 20.
The sky’s the limit: 44 minutes to break 1,012 plates. You can break this problem into more manageable chunks by reasoning that Bill breaks 230 plates in 10 minutes. Then counting up by 10-minute increments, you arrive at 460 plates in 20 minutes, 690 plates in 30 minutes, and 920 plates in 40 minutes. The remaining 80 plates will take more than 3 minutes, since 23 * 3 = 69, so all told it takes 40 + 4 minutes.
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.