Page "Japanese wordplay" Paragraph 3

Every digit has a set of possible phonetic values, due to the variety of valid Japanese ( kun ' yomi and on ' yomi ), and English-origin pronunciations for numbers in Japanese.

Often readings are created by taking the standard reading and retaining only the first syllable ( for example roku becomes ro ).

Goroawase substitutions are well known as mnemonics, notably in the selection of memorable telephone numbers for commercial services, and in the memorization of numbers such as years in the study of history.