How about 1/5th of a mile?
Or 1/20th of a mile?
Not so easy.
Easier to think in lots of 100m if you're just giving rough measurements such as driving instructions or lots of 50m for walking instructions.
Eg, go 300m past the post office and turn left.
Eg, the pub (bar) is 50m after the post office.
My tool box has 2 sets of sockets for parts from the civilised world and parts from the US.
The metric sockets go up in terms of 1mm each (eg 8mm, 9mm, 10mm, 11mm, etc) - easy.
The imperial sockets go up in inch sizes (1/2, 9/16, 5/8, 11/16, 3/4, etc) - weird and hard to calculate while I'm concentrating on the job at hand.
For the record, I grew up in Australia while we were converting from imperial to metric.
The "pain" wasn't that great and the new method (metric) is so much easier.
Any of us from schoolchild to pensioner can convert millimetres to metres to kilometres and vice-versa just by shifting the decimal point.
Converting between inches, feet, yards and miles involves oddball conversion factors (12, 3*12, 1760*3*12) that generally don't come easy to most people.
By the way, the official definition of the US inch is exactly 25.4mm.
Yep, US inches have been defined by the metric system since 1959.
http://www.ngs.noaa.gov/PUBS_L... (page 2)
ASA (American Standards Association) adopted this even earlier in 1933 and NACA (National Advisory Committee for Aeronautics, precursor to NASA) adopted it in 1952.