Go to 'thermo-' entry Go to 'dino-' entry Go to 'chondro-' entry Go to 'aero-' entry Go to '-logy' entry Go to 'thaumato-' entry Go to 'nano-' entry Go to '-sophy' entry Go to 'bucco-' entry Go to '-ism' entry Go to '-lysis' entry Go to 'galacto-' entry Go to '-anthropy' entry Go to 'pneumo-' entry Go to '-ploitation' entry Go to '-lithic' entry Go to '-sepalous' entry Go to 'onco-' entry Go to '-parous' entry Go to 'dermato-' entry Go to 'multi-' entry Go to 'dodeca-' entry Go to '-zoon' entry Go to 'vermi-' entry Go to 'crystallo-' entry Go to 'biblio-' entry Go to 'eco-' entry Go to 'juxta-' entry Go to 'facio-' entry
Affixes: the building blocks of English
Affixes: the building blocks of English

multiples

Standard systems of number prefixes.

The standard system of prefixes for multiples is that laid down in SI units (Système International D’Unités), an international agreement dating from 1960, which defines standard units for quantities and the names for the decimal prefixes to use with them.

The standard SI multiples:

deca-10Greek deka, ten
hecto-100Greek hekaton, hundred
kilo-103Greek khilioi, thousand
mega-106Greek megas, great
giga-109Greek gigas, giant
tera-1012Greek teras, monster
peta-1015Greek penta-, five, this being the fifth prefix in the series, by analogy with tera-
exa-1018Based on the Greek prefix hexa-, six, by deleting the first letter
zetta-1021Adapted from the Italian setta, seven
yotta-1024Adapted from the Italian otto, eight, with the last letter changed to match that of the other prefixes

The standard SI submultiples:

deci-one-tenth or 10-1Latin decimus, a tenth
centi-one-hundredth or 10-2Latin centum, a hundred
milli-10-3Latin mille, thousand
micro-10-6Greek mikros, small
nano-10-9Greek nanos, dwarf
pico-10-12Spanish pico, literally a little bit
femto-10-15Danish or Norwegian femten, fifteen
atto-10-18Danish or Norwegian atten, eighteen
zepto-10-21Adapted from septi-, seven, on the pattern of other multiples
yocto-10-24Similarly adapted from octo-, eight

The prefixes hecto-, deca-, deci-, and centi- are generally avoided in scientific work.

Binary multiples for computer purposes

The use of decimal prefixes to describe the similar — but not identical — binary multiples used in computing (such as megabyte or terabit) has caused confusion — as a result of various conventions, a megabyte can be 1,048,576, 1,024,000, or 1,000,000. In 1998 the International Electrotechnical Commission (IEC) agreed an international standard for a new group of prefixes that removes the ambiguity; names use the first two letters of the SI decimal prefix, followed by the letters bi, for binary. These are slowly coming into use.

kibi-210
mebi-220
gibi-230
tebi-240
pebi-250
exbi-260

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