Have you ever held a piece of gold in your hand? Maybe a gold earring, or a pen or piece of art with a bit of gold on it? Gold is a metal that is “mined,” meaning we dig it up from the earth. It is not only a beautiful color but is also easy to bend, making it a perfect material for jewelry and other small objects. It’s also not something you find easily in every backyard, so it costs a lot of money to buy. But that didn’t stop Science World from making this wild billboard. They wanted to show that gold can be spread very, very, very thin, so they covered a whole giant billboard with just 2 ounces of it! A gold hoop earring weighs about 1/8 of an ounce, so that means they used the same amount of gold as a handful of earrings, melted down and spread over hundreds of square feet. Let’s see what else we could do if we had extra gold lying around — and check out Science World’s site for other amazing science facts on billboards!
Wee ones: If your aunt wears 1 hoop earring on each ear, how many earrings does she wear?
Little kids: If 1 ounce of gold can make 8 earrings, how many pairs of earrings is that? Bonus:Then how many pairs could you make if you peeled the 2 ounces of gold off this sign?
Big kids: If a billboard is 40 feet wide and 10 feet tall, how many square feet is that sheet of gold? (In other words, if you drew lines across and down at every 1-foot mark, how many foot-wide squares would you draw?) Bonus: If you lined the bottom of a 40-foot-by-30-foot swimming pool with gold, and you needed just 2 ounces to do the billboard, how many ounces would you need for the pool?
Wee ones: 2 earrings.
Little kids: 4 pairs of earrings. Bonus: 8 pairs, since it’s twice as much gold.
Big kids: 400 square feet. Bonus: 6 ounces, since it’s just 3 times as much area as the sign.