Back in The Good Old Days, pennies were made of copper. That's not surprising -- many societies have chosen copper for their cheapest coins: it's relatively common, easy to work, and doesn't have the same shiny properties that make people go wild over gold or silver.
But in the past century, copper has become a more valuable substance.
Q: Why has copper grown more valuable? Q: Copper pennies have a mass of 2.5 grams. At the current price of $3.18 per pound, how much would it cost to make a penny out of copper?
Although the outer surface of a modern penny is still coated with copper, the bulk of its volume is a different substance. Can you figure out what it is?
Q: What is the material inside a penny? Q: How much does it cost to make a penny out of this material?
Copyright © Michael Richmond. This work is licensed under a Creative Commons License.