In the Water Margin, what does the hero of the Water Margin use to check out at the hotel?

The currency in the Northern Song Dynasty is very complicated. At that time, the main currencies were copper and iron, while Sichuan was dedicated to iron. 1000 yuan is a crane, also called consistency. In the era of Song Zhenzong (997- 1022), 16 wealthy businessmen in Chengdu printed and issued paper money instead of iron money: "Jiaozi". Jiaozi is printed with pictures of houses, trees and people. And also signed a secret record. Jiaozi can be converted into cash or circulated in the market. When you cash in jiaozi and jiaozi, you have to pay a certain commission. Old and new friends are exchanged every three years. Later, due to the misappropriation of cash by wealthy merchants in Jiaozipu, the exchange of Jiaozipu could not be guaranteed, which often caused disputes, and the government banned merchants from issuing it. 1023 (the first year of Renzong Tiansheng), issued by the government. At that time, silver was mainly cast into ingots by the state treasury and the official treasury according to the uniform fineness and weight, and generally existed only in court rewards and accounting settlement.

From this point of view, when the water margin hero checks out of the hotel, the amount will not be too large, and he still needs to pay copper or iron money. If the amount is large, they may have to pay with this money.