Sometimes larger or smaller units than SI are required.
If the length magnitude, where the unit in SI is the meter, has to be expressed in larger units, we use its multiples (kilometer, hectometer, decimeter, etc.) and to use smaller units, we use the submultiples (centimeter, decimeter, mm, etc.).
Observe the formation of multiples and submultiples of units of measurement by using the prefixes SI.
Multiples
PREFIX | SYMBOL | MEANING |
yotta | Y | 1024 |
zetta | Z | 1021 |
exhaust | AND | 1018 |
peta | P | 1015 |
will have | T | 1012 |
jig | G | 109 |
mega | M | 106 |
kilo | k | 103 |
hecto | H | 10² |
deca | gives | 10 |
Submultiples
PREFIX | SYMBOL | MEANING |
deci | d | 10-1 |
centi | ç | 10-2 |
mili | m | 10-3 |
micro | µ | 10-6 |
nano | no | 10-9 |
peak | P | 10-12 |
femto | f | 10-15 |
atto | The | 10-18 |
zepto | z | 10-21 |
yocto | y | 10-24 |
See also the simplified table:
km | hm | dam | m | dm | cm | mm |
10³ | 10² | 10 | 1 | 10-1 | 10-2 | 10-3 |
So:
1km = 1.10³
1µm = 1.10-6
1cm = 1.10-2
1nm = 1.10-9
1mm = 1.10-3
If the quantity is mass:
1kg = 10³g
1g = 10-3 kg
1g = 10³ mg
1mg = 10-3g
1g = 106µg
1 µg = 10-6
For the volume quantity, the unit of l (liter) and mL (milliliter) is much used, where:
1l = 1dm³
1mL = 1cm³
Some countries do not use metric units. They are the units of the English system (mile, yard, inch, foot, pound and ounce).
1 mile = 1609m
1 inch = 25.40mm = 2.540cm
1 yard = 0.914m
1 ounce = 28.35g
1 foot = 0.3048m
1 pound = 453.6g