Just to lighten things up a bit - I heard a fellow say that he thought that
it was a good thing we in America never adopted the metric system.  He said
the whole thing was just too vague and inaccurate. "I mean, really, a
kilometer is a 'little less' than a mile.  A kilogram is 'about' 2 and a
half pounds.  How can we deal with a system like that?"
 
Hope this helps.
 
 
Guy F. Miller   "Start every day with a smile, and get it over with."
Charlottesville VA                               W.C. Fields