There’s been some pretty scary drops in the value of some cryptocurrencies – money that only exists as computer code. Last year, for example, crypto token Terra Luna fell from about $120 to two cents in less than 48 hours, wiping out entire fortunes. In this story, correspondent Robert Holloway explains what digital currency is, why it is so volatile and why it might just last.

Exercise: Give every student a stack of “currency” with each stack labeled differently. Then on a big screen have a chart that shows the value of each slip of paper according to the color or letter. Each value will start at $1,000 so if a student has 10 slips they start off with a stack worth $10,000. Present a list of commodities they can buy at different prices. Let them see how much they can buy with their currency stack. Then change the values of the currency on the chart for different students with some going up in value and some going down in value. How does that change how much each student can buy? What does it do to their net worth? Keep changing the values so that students experience wealth and poverty depending on what value is placed on their slips of paper.