How to calculate divination with copper coins in ancient times, and how to look at the front and back?

Using copper coins to calculate divination is the knowledge in the Book of Changes. Professor Fu Peirong said that if you don't study the Book of Changes, you won't. It's not necessarily learned. You will learn to use it for life. Closer to home, the front of the copper coin represents 3; The reverse side of copper coin represents 2; Generally, three coppers add up to six, seven, eight and nine. This number is a hexagram, which becomes the lower hexagram three times in a row, the upper hexagram again and again, and the upper and lower hexagrams are combined into one hexagram. According to this hexagram, you can find the corresponding word to judge whether it is good or bad. This truth is hard to understand. You have time to learn the Book of Changes.