1 tael of gold=3,000 yuan

1 tael of silver=1 copper coin=300 yuan

1 copper coin=0.3 yuan

1 Ocean = 1 Liang of Silver = RMB 300 = 1,000 Wenqian

Mr. Huang Renyu basically used the assumption in his "The Great History of China" that 1 Liang of Gold = 10 Liang of Silver = 10 Guan, The current value of a copper coin is calculated based on the international gold price. So according to Mr.'s method, let's take a look at how much RMB the Song Dynasty's consistent exchange rate is today (July 2006).

1) The gold benchmark international price, the gold price basically fluctuates around US$400 an ounce. Let’s take $400 per ounce. One ounce is 28.3 grams. One pound made in the Song Dynasty was 640 grams ("The Jiadiao Bronze Code unearthed in Xiangtan, Hunan in 1975 weighed one hundred pounds, weighing 64 kilograms"). There are 16 taels in 1 pound, so 1 tael in the Song Dynasty was 40 grams today. In this way, one tael of gold in the Song Dynasty was equivalent to 565 US dollars, which is equivalent to 4,650 yuan based on today's US dollar to RMB 8.23 ??yuan. According to the hypothesis, it is also counted as a piece. Assume that 1 tael of gold is 10 taels of silver, that is, 10 coins. The copper coins of the Song Dynasty are equivalent to 465 yuan.

2) According to the benchmark international price of silver, the price of silver basically fluctuates around US$6 an ounce. Similar to the conversion of gold price, one tael of silver is equivalent to copper coins, which is equivalent to 70 yuan.

3) The benchmark rice price in the Song Dynasty was 640 grams per pound. In the Song Dynasty, 1 stone equaled 92.5 Song jins (Shen Kuo's Mengxi Bi Tanjuan 3 has, "For ordinary stones, ninety-two and a half jins are used as the standard, which is the Han scale of 341 jins"). Therefore, one stone of rice weighs 59,200 grams, or 59.2 kilograms. If we do not consider special famine years or great harvest years, the price of rice in the early Northern Song Dynasty was between 300 and 600 Wen per stone, in the middle period (the Renzong period) it was between 600 and 700 Wen, and in the early Southern Song Dynasty it was between 300 and 600 Wen per stone. Around 2 passes. Therefore, it is more reasonable to calculate from this that during the late Northern Song Dynasty and the reign of Emperor Huizong of the Song Dynasty, about 1 string per stone should be considered. If calculated based on the current rice price of 2.5 yuan per kilogram, one stone of rice in the Song Dynasty was 59.2 kilograms equivalent to 148 yuan, which is equivalent to 1 copper coin equivalent to 148 yuan. So far we have three prices, 465 yuan based on gold, 70 yuan based on silver and 148 yuan based on grain prices. Since our country is not a major silver-producing country, and the cost of refining silver has been greatly reduced after industrialization, the value of ancient silver must have been significantly higher than the current value. Obviously it is unreasonable to use today's silver price as a reference. This can be seen from today's silver price of 6 US dollars and the gold price of 400 US dollars per ounce. Today, one tael of gold can be exchanged for 66 taels of silver, and the ancient gold and silver exchange rate we assume is 1:10. The production of gold is stable until today. It is still used as an important hard currency reserve by countries around the world. So it makes more sense to use gold as the benchmark.

In addition, although the substantial development of modern technology and Mr. Yuan Longping's hybrid rice have greatly increased grain production, the number of people consuming grain today has also increased significantly. According to the historical geography of the Song Dynasty, the population of the Northern Song Dynasty was less than 50 million, while today China has a population of 1.3 billion. Food is the most important thing for the people, so food prices should still be an important benchmark. Therefore, the owner of Wu Zhai took the average of 465 yuan based on gold price and 148 yuan based on rice price, which was 306.5 yuan, rounded it up and removed the fractions, and set one copper coin as 300 yuan.