 
First you need the basics to understand the metric system.
The metric system is based on a decimal system (ie:powers of ten). Therefore,
it simplifies calculations by using a set of prefixes shown in the table below.
Multiplication Factor 
Prefix 
Symbol 
U.S Name 
1,000,000,000 = 10 ^{9} 
giga 
G 
billion 
1,000,000 = 10 ^{6} 
mega 
M 
million 
1,000 = 10 ^{3} 
kilo 
k 
thousand 
100 = 10 ^{2} 
hecto 
h 
hundred 
10 = 10 ^{1} 
deca 
da 
ten 
1 = 1 


one 
0.1  10 ^{1} 
deci 
d 
tenth 
0.01 = 10 ^{2} 
centi 
c 
hundredth 
0.001 = 10 ^{3} 
mili 
m 
thousandth 
0.000001 = 10 ^{6} 
micro 
µ 
millionth 
0.000000001 = 10 ^{9} 
nano 
n 
billionth 
Symbols must be written exactly as
shown in the tables. Do not change the case, or add an "s" for the
plural, or use abbreviations, or write a period after a symbol (unless it ends a
sentence).
The
symbols
(not abbreviations) for SI units are the same all over the world,
regardless
of the local language spoken.
