Metric system prefix meaning one tenth
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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
Adoption[ nb 1]
Name
Symbol
quetta
Q
1030
1000 000 000 000 000 000 000 000 000 000
2022[ 5]
ronna
R
1027
1000 000 000 000 000 000 000 000 000
yotta
Y
1024
1000 000 000 000 000 000 000 000
1991
zetta
Z
1021
1000 000 000 000 000 000 000
exa
E
1018
1000 000 000 000 000 000
1975[ 6]
peta
P
1015
1000 000 000 000 000
tera
T
1012
1000 000 000 000
1960
giga
G
109
1000 000 000
mega
M
106
1000 000
1873
kilo
k
103
1000
1795
hecto
h
102
100
deca
da
101
10
—
—
100
1
—
deci
d
10−1
0.1
1795
centi
c
10−2
0.01
milli
m
10−3
0.001
micro
μ
10−6
0.000001
1873
nano
n
10−9
0.000000 001
1960
pico
p
10−12
0.000000 000 001
femto
f
10−15
0.000000 000 000 001
1964
atto
a
10−18
0.000000 000 000 000 001
zepto
z
10−21
0.000000 000 000 000 000 001
1991
yocto
y
10−24
0.000000 000 000 000 000 000 001
ronto
r
10−27
0.000000 000 000 000 000 000 000 001
2022[ 5]
quecto
q
10−30
0.000000 000 000 000 000 000 000 000 001
Notes
^ Prefixes adopted before 1960 already existed before SI. The introduction of the CGS system was in 1873.
References