The Metic Prefixes

Since not everything weighs about the mass of a paper clip (1 gram) or is the volume of a soda bottle (1 Liter), we need to be able to describe masses, volumes, times, and lengths that are much larger or smaller than the standard unit. This is done by adding a prefix to the metric unit. 

The prefixes most commonly used in chemistry and their relationships to the base unit are shown below. There are, of course, lots of other prefixes, but in this text we will attempt to focus on what you need to know, not all information that might be considered related.

Mega means 1 million and the prefix is M, so...

1 Megaunit = 1,000,000 units (in simple English 1 Mg = 1,000,000 g and 2 ML = 2,000,000 L) 

kilo means 1000 and the prefix is k, so ...

1 kilounit = 1000 units (1kg = 1000 g and 5 kL = 5000 L) 

centi means 1/100 th and the prefix is c, however it is easier to think in whole numbers rather than fractions so... 

100 centiunits = 1 unit (100 cg = 1 g and 700 cL = 7 L) 

milli means 1/1000 th and the prefix is m. Again thinking in whole numbers rather than fractions...

1000 milliunits = 1 unit (1000 mg = 1 g and 4000 mL = 4 L) 

micro means 1/1,000,000 th and the prefix is µ (mu in the Greek alphabet -- pronounced "myoo"). Again, thinking in terms of whole numbers instead of fractions...

1,000,000 microunits = 1 unit (1,000,000 µg = 1 g and 5,000,000 µL = 5 L) 

These prefixes can be used for any of the metric units described above. Thus, 37 kilometers is the same distance as 37,000 meters, and 4.89 liters is the same as 4,980,000 microliters, etc.