Calculator spelling is an unintended characteristic of the seven-segments display traditionally used by calculators, in which, when read upside-down, the digits resemble letters of the Latin alphabet. Each digit may be mapped to one or more letters, creating a limited but functional subset of the alphabet, sometimes referred to as beghilos (or beghilosz).
Aside from novelty and amusement, calculator spelling has limited utility. The popularity of pagers in the 1990s gave rise to a form of leetspeak called pagerspeak. Students, in particular, experimented with calculators to discover new words.
The ‘original’ attributed example of calculator spelling, which dates from the 1970s, is 5318008, which when turned over spells “BOOBIES”. Another early example of calculator spelling offered the sequence 0.7734, which becomes “hello”, or could also be written as “0.1134”. Other words possible with the traditional “BEghILOSZ” set include “LOOSE”, “ShELL”, “BEIgE”, “gOBBLE”, “gOOgLE”, and many others. Among the longest are “hILLBILLIES” and “SLEIghBELLS” at 11, and “gLOSSOLOgIES” and “BIBLIOLOgIES” at 12 letters. Another common case, 7734206, spells “gO 2 hELL”, or with a capital G, it would be “7734209” 8008 is special in that it can spell “BOOB” upside-down or right-side up. Also, 8055 right side up reads “BOSS”. 71077345 spells “SHELLOIL”. There are also a couple of names that are able to be calculator spelled. For example, 7718=BILL, and 5107=LOIS.
Scientific calculators that feature hexadecimal readout using the letters A through F offer more flexibility. Using a scientific calculator with hex capability, the earlier “5318008” example can be improved with the A–F keys to spell “B00B1E5”, without needing to rotate the display (a practice known as hexspeak or Base 16). The Hexspeak Version of “B00B1E5” is 184,594,917.
Students often use this capability and the improved “alpha” feature that use the letters “A” through “Z” to write messages, separating words by using the minus sign (“-“) or other punctuation. In the “B00B1E5” example above, for instance, a factorial product sign (“!”) can be added to create “B00B1E5!” Most of these calculators do not use seven-segment displays, instead using dot matrix displays for greater versatility.