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Prefixes

Metric Units of Measurement

In the metric system of measurement, designations of multiples and subdivision of any unit may be arrived at by combining with the name of the unit the prefixes deka, hecto, and kilo meaning, respectively, 10, 100, and 1000, and deci, centi, and milli, meaning, respectively, one-tenth, one-hundredth, and one-thousandth. In some of the following metric tables, some such multiple and subdivisions have not been included for the reason that these have little, if any currency in actual usage.

In certain cases, particularly in scientific usage, it becomes convenient to provide for multiples larger than 1000 and for subdivisions smaller than one-thousandth. Accordingly, the following prefixes have been introduced and these are now generally recognized.


Prefixes
Purpose
Prefix Name
Pronunciation
Prefix Symbol
Value


larger quantities
or whole units
yotta yot'uh Y 1024 Septillion
zetta zet'uh Z 1021 Sextillion

exa

ex'a
a as in about
E
1018
Quintillion
peta
as in petal
P
1015
Quadrillion
tera
as in terrace
T
1012
Trillion
giga
jig'a
a as in about
G
109
Billion
mega
as in megaphone
M
106
Million
kilo
as in kilowatt
k
103
Thousand
hecto
heck'toe
h
102
Hundred
deka
deck'a
a as in about
da
101
Ten
 


100
One
smaller quantities
or sub units


deci
as in decimal
d
10-1
Tenth
centi
as in sentiment
c
10-2
Hundredth
milli
as in military
m
10-3
Thousandth
micro
as in microphone
μ
10-6
Millionth
nano
nan'oh
an as in ant
n
10-9
Billionth
pico
peek'oh
p
10-12
Trillionth
femto
fem'toe
fem as in feminine
f
10-15
Quadrillionth
atto
as in anatomy
a
10-18
Quintillionth
zepto zep'toe z 10-21 Sextillionth
yocto yok'toe y 10-24 Septillionth


Whole Units
Decimal Units
thousands
hundreds
tens
basic unit
tenths
hundredths
thousandths
1000
100
10
1
0.1
0.01
0.001
kilo-
hecto-
deka-
meter
gram
liter
deci-
centi-
milli


Units of Length

10 millimeters (mm) 1 centimeter (cm)
10 centimeters 1 decimeter (dm) = 100 millimeters
10 decimeters 1 meter (m) = 1000 millimeters
10 meters
1 dekameter (dam)
10 dekameters
1 hectometer (hm) = 100 meters
10 hectometers
1 kilometer (km) = 1000 meters


Units of Area

100 square millimeter (mm2)
1 square centimeter (cm2)
100 square centimeter 1 square decimeter (dm2)
100 square decimeters 1 square meter (m2)
100 square meters 1 square dekameter (dam2) = 1 are
100 square dekameters
1 square hectometer (hm2) = 1 hectare (ha)
100 square hectometers
1 square kilometer (km2)


Units of Liquid Volume

10 milliliters (mL)
1 centiliter (cL)
10 centiliters
1 deciliter (dL) = 100 milliliters
10 deciliters
1 liter1 = 1000 milliliters
10 liters
1 dekaliter (daL)
10 dekaliters
1 hectoliter (hL) = 100 liters
10 hectoliters
1 kiloliter (kL) = 1000 liters


Units of Volume

1000 cubic millimeters (mm3)
1 cubic centimeter (cm3)
1000 cubic centimeters
1 cubic decimeter (dm3)
1 000 000 cubic millimeters
1000 cubic decimeters

1 cubic meter (m3)

1 000 000 cubic centimeters
1 000 000 000 cubic millimeters



Units of Mass

10 milligrams (mg)
1 centigram (cg)
10 centigrams 1 decigram (dg) = 100 milligrams
10 decigrams 1 gram (g) = 1000 milligrams
10 grams 1 dekagram (dag)
10 dekagrams
1 hectogram (hg) = 100 grams
10 hectograms
1 kilogram (kg) = 1000 grams

1000 kilograms

1 megagram (Mg) or 1 metric ton(t)



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