Deci-

From HandWiki
French 1 decime coin, equal to 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,[1] and adopted in 1795, the prefix comes from the Latin decimus, meaning "tenth". Since 1960, the prefix is part of the International System of Units (SI).[2][3]

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.[4]
Prefix Base 10 Decimal English word Adoption[nb 1]
Name Symbol Short scale Long scale
yotta Y  1024 1000000000000000000000000  septillion  quadrillion 1991
zetta Z  1021 1000000000000000000000  sextillion  trilliard 1991
exa E  1018 1000000000000000000  quintillion  trillion 1975
peta P  1015 1000000000000000  quadrillion  billiard 1975
tera T  1012 1000000000000  trillion  billion 1960
giga G  109 1000000000  billion  milliard 1960
mega M  106 1000000  million 1873
kilo k  103 1000  thousand 1795
hecto h  102 100  hundred 1795
deca da  101 10  ten 1795
 100 1  one
deci d  10−1 0.1  tenth 1795
centi c  10−2 0.01  hundredth 1795
milli m  10−3 0.001  thousandth 1795
micro μ  10−6 0.000001  millionth 1873
nano n  10−9 0.000000001  billionth  milliardth 1960
pico p  10−12 0.000000000001  trillionth  billionth 1960
femto f  10−15 0.000000000000001  quadrillionth  billiardth 1964
atto a  10−18 0.000000000000000001  quintillionth  trillionth 1964
zepto z  10−21 0.000000000000000000001  sextillionth  trilliardth 1991
yocto y  10−24  0.000000000000000000000001  septillionth  quadrillionth 1991
  1. Prefixes adopted before 1960 already existed before SI. 1873 was the introduction of the CGS system.

References