Gold on Fire

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

Gold on Fire

November 30, 2015

The shiniest spot on the Statue of Liberty is the flame on her torch. It’s made of copper inside, but coated in a thin layer of gold, the same beautiful metal in jewelry. So Bedtime Math fan Emerson S. asks, how much gold is on that flame? That torch looks tiny because it stands more than 300 feet off the ground, but the ball-shaped flame is BIG. It looks about the same height as her pointy finger, which is 8 feet tall. As we’ll see below, that comes to a couple hundred square feet. But gold can be pounded really, really thin: 1 ounce of gold, which is 1/2 the weight of a candy bar but only the size of a quarter, can spread to cover up to 100 square feet! That’s about the size of your bedroom floor. Thankfully, jeweler Kristen Reyes found the actual answer for us: the torch is covered in 5,000 little 3-inch square sheets that weigh less than 6 ounces total. The flame was gilded just in 1985, and it still shines in the sun today.

Wee ones: Who’s taller, you or that 8-foot-tall flame? Find out your height in feet!

Little kids: If a candy bar weighs 2 ounces, how many 1-ounce pieces of gold would match 2 candy bars?  Bonus: If you can make 2 gold earrings from each ounce of gold, how many earrings can you make?

Big kids: The “surface area” around a ball is always 4 times pi (3.14) times the radius times the radius again, where the radius is 1/2 the distance across. What’s the surface area of the Statue’s 8-foot flame? (You can round pi to 3.)  Bonus: If you peeled off one of those 5,000 sheets of gold for yourself, how many would be left?

 

 

 

Answers:
Wee ones: The flame is taller…almost no people are 8 feet tall!

Little kids: 4 pieces.  Bonus: 8 earrings.

Big kids: About 192 square feet, without the fingers of flames.  Bonus: 4,999 sheets.

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About the Author

Laura Overdeck

Laura Overdeck

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 while still in diapers, 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.

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