When we eat, most of us like to sit still. But some restaurants spin you while you eat! The Space Needle in Seattle has a restaurant 500 feet off the ground (about as tall as a stack of 15-20 houses). It makes 1 full turn every 47 minutes. Meanwhile, the CN Tower in Toronto, Canada has the 360 Restaurant, spinning a dizzying 1,151 feet above the ground once every 72 minutes. The biggest turning restaurant of all is Bellini in Mexico City, which takes 1 hour 45 minutes to turn — giving you even more time to munch.
Wee ones: Find something in your room that turns on its own. Does it turn quickly or slowly? If you can make it turn, which way do you spin it?
Little kids: Which restaurant is turning faster, one that takes 40 minutes to turn or one that takes 50 minutes? Bonus: If you can eat a plate of food every 10 minutes, how long does it take to eat 6 plates? Count up by 10s!
Big kids: The Space Needle itself is 605 feet tall. If you’re in the restaurant at 500 feet, how many feet do you have to climb to reach the top of the needle? Bonus: If you can eat 2 bites of food every minute, will the 360 Restaurant give you enough time to eat a 100-bite burger and 40 bites of fries in one spin? (The “360” turns in 1 hour 12 minutes.)
The sky’s the limit: If SkyCity, the Space Needle restaurant, spins once every 45 minutes and the huge Bellini in Mexico City speeds up to turn once every 60 minutes, and they both start turning at 6 pm with their front doors both facing south, when’s the next time their front doors will face the same direction as each other?
Wee ones: Items might include the second hand on a watch or clock, dials on gadgets, or a doorknob.
Little kids: The one that takes 40 minutes: if it takes less time, it’s turning faster! Bonus: 10, 20, 30, 40, 50, 60.
Big kids: 105 feet. Bonus: Yes: 1 hour 12 minutes is 72 minutes, enough for 144, whereas your meal has 140 bites.
The sky’s the limit: In 3 hours, they’ll both be facing south. SkyCity will take only 3/4 hour to turn, while Bellini will take 1 hour. They’ll face the same direction again when Space Needle has done exactly 1 more turn than Bellini. To solve for that:
In time t (in hours), S will make 4/3 t turns.
In time t (in hours), M will make 1 t turns, and that will be 1 less turn than S makes.
So 4/3 t – 1 = t
Multiplying by 3,
4t – 3 = 3t
4t – 3t = 3
t = 3
So t = 3 hours. At that point SkyCity would have made exactly 4 turns and Bellini, 3 turns.
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.