Invention: Coin and measures

The Qin Dynasty standardized their currency that helped their economy. For example, taxes and salary were often paid in grain or produce. Qin needed a system of weight and measures also. They solved this problem by having standard sized clay cups to measure liquid and grain. Next for money management two more coins were introduced copper and gold each having a square shaped hole in the middle. This characteristic made them different from any other coins. The round shape coin represented heavens and the square represented the Earth.