What Makes Money Work: teacher key

Money, grade 7 edition, written for 7th grade. Barter had a built-in problem that money solved. Follow money from cowrie shells and the first stamped metal to paper receipts, dollar bills and bank deposits.

Read the book. Print this page for the key.

Questions and answers

1. What is the double coincidence of wants?
   • A coin has two faces
   • A trade works only when both people have something the other wants (answer)
   • Two banks insure one deposit
2. Which of these is a trait of good money?
   • Heavy
   • Secret
   • Durable (answer)
3. What did Lydian stamping let people trust?
   • The metal's weight and purity (answer)
   • A bank's insurance
   • A bill's color
4. Why did paper money begin in China?
   • The Mint Act required it
   • Merchants traded receipts from deposit shops instead of carrying heavy strings of coins (answer)
   • Cowrie shells ran out
5. How long does a $1 bill last on average, as of November 2026?
   • 72 years
   • 7.2 days
   • 7.2 years (answer)
6. What is opportunity cost?
   • Whatever must be given up to get something else (answer)
   • The price of a bank deposit
   • The weight of a coin

Words

• barter: trading goods
• durable: lasts long
• deposit: money put in
• principal: amount deposited
• watermark: faint hidden picture