Chinese Yi Jing [I Ching] employs binary and octal numbering systems.
Here is brief description of the binary and octal numbers.
In binary numbering system, 2 possible numbers can be expressed with "one binary digit" :
0 1
Of course, it is entirely arbitrary to adopt "0" and "1" as the symbols
for these two possible numbers. In Yi Jing, we use "broken line" and "solid line"
to represent the two numbers 0 and 1 respectively  like this:
0 

1


In English, the name of the symbol "0" is "zero", and the name of the symbol "1" is "one."
In Ba Gua, the name of the symbol "0" in "ying", and the name of the symbol is "yang."
Furthermore, instead of calling these two symols "zero" and "one", we
may choose to call them "one" and "two", which we often do when we
speak of these as part of "digital numbers."

Using two binary digits, there are 4 possible numbers:
00
01
10
11
The Yi Jing symbol representations are:
The two binary numbers are place horizontally and should be read from left to right.
The Bagua numbers are placed on a vertical line, and should
be read from bottom up

Going up to three binary digits, there are 8 possible numbers:
000
001
010
011
100
101
110
111
These 8 numbers can be expressed in decimal system. We may choose to
use these 8 numbers to represent 0 to 7; or to repsent 1 to 8. See below:
000 0 1
001 1 2
010 2 3
011 3 4
100 4 5
101 5 6
110 6 7
111 7 8


Binary 
Digital 
Yi Jing symbol 
Ba Gua Name 
000 
0 
1 
 kun1 
001 
1 
2 
 gen4 
010 
2 
3 

kan3 
011 
3 
4 

sun4 
100 
4 
5 
 zhen 
101 
5 
6 
 li2 
110 
6 
7 
 dui1 
111 
7 
8 

qian2 
This is what modern mathematicians call the "octal numbers" and Yi Jing
calls "Ba Gua."
Both words, "octal" and "Ba", stand for 8.
Finally, 8 times 8 equals 64.
This requires either 6digit binary numbers, or 2digit octal numbers.
As it turns out, 6 binary digit numbers are awkward to use. So we
use twodigit octal numbers in Yi Jing (Ba Gua).
Instead of writing a long list of 64 numbers, it is better to
put the numbers in a square with 8 x 8 = 64 cells.
The row number represents one octal number, and the column number
represents one octal number.
