Deci-

File:France, decim 1798-1799, the First Republic.jpg coin, equal to {{sfrac|1|10}} of a franc. First Republic.]]

Deci (symbol d) is a decimal unit prefix in the metric system denoting a factor of one tenth. Proposed in 1793,{{cite book|title=Instruction abrégée sur les mesures déduites de la grandeur de la Terre; uniformes pour toute la Rêpublique, et sur les Calculs relatifs à leur division décimale

|author=Commission temporaire de Poids & Mesures rêpublicaines, En exécution des Décrets de la Convention Nationale

|publisher=De l´imprimerie nationale exécutive du Louvre

|edition=Edition originale

|location=Paris, France

|language=fr

|date=1793

|url=https://archive.org/details/instructionabreg00hauy

|access-date=2015-10-09}} and adopted in 1795, the prefix comes from the Latin {{lang|la|decimus}}, meaning "tenth". Since 1960, the prefix is part of the International System of Units (SI).{{cite book

| title=The International System of Units (Si): The Metric System

| page=30

| publisher=DIANE Publishing

| year=1992

| url=https://books.google.com/books?id=y2-BDaoBVnwC&dq=si+derived+units+1960&pg=PA30

| isbn=9780941375740}}{{cite web

| url=https://www.bipm.org/en/CGPM/db/11/12/

| title=Resolution 12 of the 11th CGPM

| date=1960

| publisher=BIPM

| access-date=2020-05-14

| archive-date=2020-04-08

| archive-url=https://web.archive.org/web/20200408155740/https://www.bipm.org/en/CGPM/db/11/12/

| url-status=dead

}}

A frequent use of the prefix is in the unit deciliter (dl), common in food recipes; many European homes have a deciliter measure for flour, water, etc. A common measure in engineering is the unit decibel for measuring ratios of power and root-power quantities, such as sound level and electrical amplification.

Example

The diameter of a compact disc is about 12 centimetres or 1.2 decimetres.{{cite web

| title=Universcale: From the nanoworld to the universe — The worlds we measure using our infinite yardstick.

| publisher=Nikon

| date=2013

| url=https://www.nikon.com/about/sp/universcale/

| url-status=live

| archive-url=https://web.archive.org/web/20170208212202/http://www.nikon.com/about/sp/universcale/index.htm

| archive-date=2017-02-08

| access-date=2017-02-08}}

References

Category:SI prefixes