Before Qin Shihuang unified the whole country, it was a chaotic Warring States period. During the Warring States period, countries competed for hegemony, so each country had its own exclusive currency. Just like when we go abroad now and go to another country, we have to change money first. According to historical records, four currencies were widely circulated during the Warring States Period. Divided into cloth coins, copper shell coins, square hole coins and knife coins.

Among them, cloth coins are mainly circulated in Wei, Zhao, South Korea and other countries. This kind of cloth coins seems to be shovels to us modern people, but there are also kinds of cloth coins, which may have different values, such as empty cloth, round shoulders and square feet, square shoulders and so on. It is also used by more people.

The second kind of copper shell is mainly popular in Chu State. Because it looks more like an ant's nose, it is often called ant nose money. And this copper shell is the golden cake cast by Chu State.

The third kind is the money we often see. At that time, this kind of money was only used in Qin and two small countries, East and West Zhou. However, in order to distinguish, the East and the West cast the name of their country on the hole of their country every two weeks, and Qin only set the value unit of this hole. Later, after Qin Shihuang unified the world, he also asked to unify the national currency on the basis of Qin Banwen.

The last one is a knife coin, which, as the name implies, looks like a knife. Knife coins are mainly circulated in Qi State and Yan State.

The above is my personal view on this problem, I hope I can help you, thank you.