The currency used by the people of the Shang Dynasty was shellfish, including sea shells, bone shells, stone shells, jade shells and copper shells. The appearance of copper shells shows that the Shang Dynasty already had metal-cast currency.

The development of commerce requires currency. The earliest currency used in my country during the Shang Dynasty included, in addition to real shells, bone shells and cast copper shells. The emergence of copper shells illustrates the Shang Dynasty There are already currencies made of metal. Shell coins are classified into: cargo shells and copper shells. Shell coins are classified according to size: (1) Large shell (2) Strong shell (3) Small shell (4) Small shell (5) Small shell that is not oversized

Big shells are more than four inches and eight cents, two pieces For a friend, two hundred and sixteen. The strong shells are more than three inches and six cents long, two shells make up a penn, and they are as straight as fifty. The shells are more than two inches and four cents long, and two shells make a pen, which is up to thirty. The size of a small shell is more than two cents, and two pieces make a pen, which is straight to ten. If you don't have enough money, you can't be a friend. If you don't have enough money, you can't be a friend. It is the fifth grade of shellfish. "Book of Han·Shi Huo Zhi"

Ten two-inch small shell coins are one string, and two strings are one peng. Straight one hundred.

A coins are divided into four categories:

(1) Ten friends are one big Jia. Straight two thousand one hundred and six.

(2) Ten pennies are one armor, worth five hundred,

(3) Ten pennies are one armor, worth three hundred,

(4 ) Ten friends are a small armor, straight to a hundred.