Conversion within the metric system is simply a matter of counting decimal places.

Measures for length (meter), volume (liter), or weight (gram) all use the same prefixes.

Kilo means 1000, so a kilometer is 1000 meters

                                                                          A kiloliter is 1000 liters

                                                                                                             A kilogram is 1000 grams

Centi means one hundredth (1/100), so

a centimeter is 1/100 of a meter or another way to think of it is it takes 100 cm to make a meter.

A centiliter is 1/100 of a meter  (100 centiliters make one liter)

A centigram is 1/100 of a gram (100 centigrams make one gram)

prefix
symbol
size
kilo
k
1000
hecto
h
100
deka
da
10
base unit
 
1
deci
d
0.1 or 1/10
centi
c
0.01 or 1/100
milli
m
0.001 or 1/1000
 
The diagram below shows the prefixes up to 1000 and down to one one-thousandth (1/1000).

 

 

To convert 1.12 m to mm  we would start at the base 1 step (liter, meter, or gram).  We would go down 3 steps to the right so we move the decimal 3 places to the right putting in zeros as necessary.

1.12 m = 1120 mm

Using this method, convert .45 cl (centiliters) to liters.  This time we start on the centiliter step and count up to the left 3 steps so we move the decimal 3 places to the left to get .00045 liters.

Once you get the hang of this, you don't really need the stairs.  You can write the units in a line and simply count left or right to see how many places to move the decimal.

kilo           hecto            deca           BASE (m, l, or g)            deci               centi           milli

Although all the prefixes can be used for any of the bases, the most common metric units you see are:

kilograms, grams, and milligrams

kiloliters, liters, milliliters

kilometers, meters, centimeters, milliliters

If you prefer, you can memorize those conversion factors and work these problems using unit cancelation like the examples in the English system conversions found on http://www.vhcc.edu/sfleming/MTH02/Unit conversion.htm

For lots more information on the metric system visit http://king.prps.k12.ca.us/prhs/pasohigh/classes/Fairbank/public.www/homepage/chemist/metric/Metrhome.htm