Before the Song Dynasty, eight-character fortune telling used the fortune-telling method, using the year to represent oneself, and the five elements of Nayin in the year of birth to represent the five elements of this life. For example, this year's Jiawu, Nayinsha has gold, and people born this year have a gold life.
After Xu Ziping appeared in the Song Dynasty, the Rizhu and Tiangan among the four pillars represented the life master. The five elements of the Rizhu and Tiangan were the five elements of the life master. If the Rizhu was Jiawu, then Jiamu represented the five elements of the life master. .
As for the number of elements of the Five Elements, it cannot be explained in one sentence if you look at the specific eight characters.