The major system (also called the phonetic number system, phonetic mnemonic system, or Hérigone's mnemonic system) is a mnemonic technique used to help 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 similar systems of Pierre Hérigone and Richard Grey with uses by Lewis Carroll and Gottfried Wilhelm Leibniz.[1]