The banker's benchRosa's mother was a merchant in an old town in Italy. She traveled with a heavy sack of coins, but nobody could watch it. In the town square, a banker sat at a long bench. In his language a bench was a banco, and that is where our word bank comes from. She asked him to keep her coins safe. He locked them in a strong box and wrote the amount in a big book. He gave her a paper slip that said how many coins she had left there. A week later, she came back with the slip, and he handed back her sack. Dario the baker wanted a new oven, so he borrowed six pretend coins and later paid back seven. The extra coin is called interest.