Bagua positions and numbers in I-Ching

The positions of the Bagua or the eight trigrams deals with the essential concept of change in I-Ching. Lets look at the opposite pairs of trigrams. Each is a change of its opposite trigram. There are four different types of changes. Firstly, the reflective type: Kan and Li where each 1 changes into a 0 and vice versa. Secondly, the upside-down type:  Zhen and Dui.  Thirdly, change the top type: Gen and Kun.  And fourthly, change the bottom type: Qian and Xun.  For one who has an intuitive understanding of numbering system, he can readily observe that these four types are not exhaustive, say, there can be a type changing the middle, or more elaborated one like changing reflective first then change the top one!  What I am trying to say is the bagua only gives major changes, whereas in real life, any adaptive system must have an infinite possibility of change, assuming that all is feasible.  This kind of infinite possibility, I believe, is the profound teaching of change in I-Ching.

How about the numbers?  The numbers are actually not part of I-Ching and are from another numbering system called Luoshu (洛書).  Without going into details, these are the numbers of the Luoshu system, with an additional five in the middle.  Using the numbering system of Luoshi, each trigram now has a associate number.  One can easily observe the symmetry of this numbering system without me taking the trouble of pointing it out (if you can't see the symmetry, forget about I-Ching, it's not your cup of tea).

Many ancient practices in China made use of I-Ching to sanctify their practice.  Taoist yoga (meditation or Neidan) being one.  The metaphor of Kan and Li is being used, as I explained in previous posts. 

The numbering system of Luoshi likewise is being sanctified after associating with I-Ching.  And one applied usage has been passed along traditional Chinese commercial practice.  The nine sections of one's second, third and fourth fingers are used to signify the Bagua numbers with the additional number of five in the middle.  I was told that jade traders used to point his seller's or buyer's respective finger positions to make an offer as well as to do subsequent price negotiation, without other people knowing the detail negotiation nor the final striking price.  Presumably experienced jade traders can sell or re-sell their pieces to the uninitiated at a higher price!