Robots pretty much always look cool, no matter what shape they have. Some are boxy, some are round. Some have lights, some have buttons. One of the world’s favorite robots is little BB8 from the latest Star Wars movie. He’s just a white and orange ball that rolls and makes cute beeping sounds, so he’s pretty simple. But maybe that’s why he’s so cute. Well, our friend and fan Caitlyn R. just sent us a great photo and video about him: Someone made a car wheel that looks just like BB8, with BB8’s head resting just above the tire. So as the wheels turn, it looks like BB8 is holding up the car! That made us realize we could paint a lot of fun, round objects on car wheels. Why stick with boring black tires and silver hubs, when that wheel could look like a donut or a Ferris wheel? As we run the numbers on this, the fun wheels add up fast.
Wee ones: What shape is a car tire?
Little kids: If that car’s 1 wheel looks like BB8 and the rest are plain, how many plain wheels does the car have? Bonus: If you have 2 cars and paint all the left-side wheels to look like chocolate chip cookies, how many cookie wheels are there?
Big kids: If the car has 1 BB8 wheel, and another wheel that looks like a donut with sprinkles, how many different ways can you place the BB8 wheel and donut wheel on the car? Bonus: If the BB8 rolls that car 100 feet per minute, can he drive the car to a donut shop 1 mile away within 1 hour? (Reminder if needed: A mile has 5,280 feet.)
The sky’s the limit: If you have a fleet of 20 cars, and of all their wheels, there are twice as many donut wheels as BB8 wheels, and the same number of cookie wheels as donut wheels, what’s the greatest number of BB8s there can be?
Wee ones: A circle, from the side. In 3D it’s an “annulus” (ring shape).
Little kids: 3 plain wheels. Bonus: 4 cookie wheels.
Big kids: 12 ways: for each of the 4 spots for the BB8 wheel, there are 3 different spots the donut wheel can go. Bonus: Yes! He can roll the car 6,000 feet in that time.
The sky’s the limit: 16 BB8 wheels. If there’s 1 set of BB8s, then there are 2 sets of just as many donuts and cookies, making 5 equal-sized sets in total. There are 80 wheels in total — remember, each of those 20 cars has 4 wheels! — and 1/5 of 80 is 16. So that’s how many wheels make up the BB8 set, and there are 32 donuts and 32 cookies.