北宋时期 ,益州 (四川古称 )的农业、手工业和商业在唐、五代繁荣的基础上进一步发展 ,成为全国经济最繁盛的地区之一。由于工商业的发展 ,货币的需要量大为增加。益州当时又是使用铁钱的地区。铁钱币值低 ,重量大 ,买一匹丝织的罗 ,需要铁钱 2万 ,重约 1 30斤 ,携带起来很不方 During the Northern Song Dynasty, the agriculture, handicrafts, and commerce of Yizhou (the ancient name of Sichuan) were further developed on the basis of the prosperity of the Tang and the Five Dynasties and became one of the most prosperous areas in the country. Due to the development of industry and commerce, the demand for currency has greatly increased. Yizhou was then used to use iron money. Iron coins are of low value and heavy weight. To buy a silk-weaving Luo, you need 20,000 tons of iron and weigh about 30 pounds.