I can't tell the numbers from the hexagrams in the Book of Changes. Thank you.

Gan 1, dui 2, Li 3, Zhen 4, Xun 5, Kan 6, Gen 7, Kun 8.

The first remainder divided by 8 is the last one (if it is divisible, it is 8, that is, Kun).

The second remainder is divided by 8, and then divided by the remainder of 8 (if divisible, it is recorded as 8, that is, Kungua).

The third remainder is divided by 8 and then divided by the remainder of 8, counting from bottom to top. If you don't count to the last one, count from top to bottom. If the remainder is 8, the change is 5. However, there are many methods of divination based on numbers, and this is just one of them.