Smaller Measurement from a  tonne 

1 kilogram
(1 kg)

 
A thousand grams (1000 g)
is the mass of 1 kg (1 kilogram).
And 1 kilogram is simply written 1 kg
•
Pronounced "KILL-oh-gram"
NOT "kill-AH-gram".

 Smaller Measurement from a  kilogram

1 gram
(1 g)

 
Remember that kilo is the prefix
meaning 1000 times,
which only says that there are
1000 g (grams) in 1 kg (kilogram)
and we simply write 1 g to represent
the mass of 1 gram.

Smaller Measurement from a gram

1 milligram
    (1 mg)

 
Remember, milli is the prefix meaning
1 one thousandth (0.001).
So, 1 one thousandth from the
unit of measurement gram
being 1 milligram, is
simply written 1 mg.