Hexagram Flashcards first displays the hexagram by itself, then adds the identifying information as if turning over a flashcard. One may flip through the cards in any of the following sequences: King Wen, binary, binary paired, or shuffled.
Click on one of the sequences to choose it, or to start over.
Use the spacebar to turn over the current flashcard (that is, to show the name and number of the current hexagram), then to show the next flashcard (the next hexagram), and so on.
Use the right (forward) and left (backward) arrow keys to scroll directly through the hexagrams.
To show the flashcards in reverse order, alternate the left arrow key and the spacebar.
Automate runs at two different speeds depending on which side of the card is showing.
Hexagram information includes the King Wen number, the Chinese (Pinyin and Wade–Giles, if different) and English hexagram names, the English trigram names, the decimal value (hexagram read as a binary number), and the octal value (base 8, the values of the trigrams). I consider the latter to be the most useful way of numbering the hexagrams, as described below. The English hexagram names are eclectic, mostly based on either Richter or Wilhelm.
Binary hexagram numbering
Hexagrams may be treated as six-digit binary numbers. Each line represents one digit; typically, yin = 0 and yang = 1. The digits of binary, or base 2, numbers are ascending powers of 2. The first, or bottom, digit is 1, followed by 2, 4, 8, 16, and finally 32 at the top. (In binary notation, these numbers are 1, 10, 100, 1000, 10000, and 100000.) For example, to read the binary value of hexagram 49 directly, add the values of all the digits that are 1, or yang, which in this case are 1 + 4 + 8 + 16 = 29.
Hexagram 49, Revolution:
The trigrams, handy mnemonic devices that they are, provide a shortcut. Note that the value of each of the lines in the upper trigram is 8 times the value of the corresponding line in the lower trigram. It is not hard to learn to recognize the values of all eight trigrams by sight. All one then has to do is multiply the value of the upper trigram by 8, and add the value of the lower trigram. So for hexagram 49, the value of the upper trigram, 3, is multiplied by 8 to give 24. Adding the value of the lower trigram, 5, yields the hexagram’s value, 29.
Reading the trigram values directly actually turns the hexagrams into two-digit octal, or base-8, numbers, in this case 35 for Lake, 3, over Fire, 5. One might argue that this is the most intiuitve way to number the hexagrams. I have added the octal numbers of the hexagrams to The Pocket I Ching Oracle.
For more information on hexagram numbering, see The Case for Little-Endian.