Concept
The major system (also called the phonetic number system, phonetic mnemonic system, or Herigone's mnemonic system) is a mnemonic technique used to aid in memorizing numbers. The system works by converting numbers into consonants, then into words by adding vowels. The system works on the principle that images can be remembered more easily than numbers. One notable explanation of this system was given in Martin Gardner's book The First Scientific American Book of Mathematical Puzzles and Diversions (just Mathematical Puzzles and Diversions in the UK edition), which has since been republished in The New Martin Gardner Mathematical Library as Hexaflexagons, Probability Paradoxes, and the Tower of Hanoi. In this, Gardner traces the history of the system back to Pierre Hérigone and Richard Grey with uses by Lewis Carroll and Gottfried Wilhelm Leibniz. Each numeral is associated with one or more consonants. (In other words, the link is to the sound, not the letter. For example, the letters C in "cat", "Cynthia", and "cello" each have different values in the system – 7, 0, and 6, respectively.) Vowels, semivowels and the consonant /h/ are ignored. These can be used as "fillers" to make sensible words from the resulting consonant sequences. A standard mapping is: The groups of similar sounds and the rules for applying the mappings are almost always fixed, but other hooks and mappings can be used as long as the person using the system can remember them and apply them consistently. Each numeral maps to a set of similar sounds with similar mouth and tongue positions. The link is phonetic, that is to say, it is the consonant sounds that matter, not the spelling. Therefore, a word like action would encode the number 762 (/k/-/ʃ/-/n/), not 712 (k-t-n). Double letters are disregarded when not pronounced separately, e.g. muddy encodes 31 (/m/-/d/), not 311, but midday encodes 311 (/m/-/d/-/d/) while accept encodes 7091 (/k/-/s/-/p/-/t/) since the ds and cs are pronounced separately. x encodes 70 when pronounced as /ks/ or /gz/ (e.