Editing Deca- (section)

{{Short description|Numerical prefix meaning "ten"}}
{{Other uses|Deca (disambiguation){{!}}Deca}}
{{Wiktionary|deca-}}
{{Wiktionary|deca-|deka-|dec-}}

'''Deca''' (and '''dec'''), sometimes '''deka''', is a common [[English language|English-language]] [[numeral prefix]] derived from the [[Late Latin]] {{Lang|la|decas}} ("(set of) ten"), from [[Ancient Greek]] {{Lang|grc|δεκάς (dekás)}}, from {{Lang|grc|δέκα}} (déka, "[[10 (number)|ten]]").<ref>{{Cite book|title=Chambers Twentieth Century Dictionary|date=1979|page=332}}</ref>  It is used in many words.

It is also a [[decimal prefix|decimal]] [[unit prefix]] in the [[International System of Units]] (SI) denoting a factor of ten, with symbol '''da''' and spelled "'''deca'''" internationally{{efn|As used by the [[International Bureau of Weights and Measures]].<ref name="bipm-spelling">[https://www.bipm.org/en/publications/si-brochure/chapter3.html ''Decimal multiples and submultiples of SI units''] {{Webarchive|url=https://web.archive.org/web/20190330005801/https://www.bipm.org/en/publications/si-brochure/chapter3.html |date=2019-03-30 }}, 2006, SI Brochure: The International System of Units (SI), 8th edition</ref>}} (or "'''deka'''" in [[American and British English spelling differences#-re, -er|American spelling]]<ref name=SP811>[http://physics.nist.gov/Pubs/SP811/sp811.html ''Guide for the Use of the International System of Units (SI)''], 1995, NIST Special Publication 811</ref>).