metric is used world-wide and is used everywhere except in english places (britan and USA)
some examples why metric is nice
base 10 system
1cm=10mm=0.1m=0.01km
1cm^3=1ml
1000cm^3=1L
1000ml=1L
0 C⁰=freezing tempurature
100 C⁰=boinling tempurature
in english
12in=1foot
3ft=1yd
16oz=1lb
8oz=1cup
3tsbs=1tbs
2c=1pt
2pt=1qt
4qt=1gal
32 F⁰=freezing
2hundred something=boiling
metric is nice because everything is in multiplules of 10
and also this exerpt from a book
"In metric, one milliliter of water occupies one cubic centimeter,
weighs one gram, and requires one calorie of energy to heat up by one
degree centigrade which is 1 per cent of the difference between its
freezing point and its boiling point. An amount of hydrogen weighing the
same amount has exactly one mole of atoms in it. Whereas in the American
system the answer to 'How much energy does it take to boil a
room-temperature gallon of water?' is go **** yourself because you
can't directly relate any of those quantities "