Puckdropper wrote:
wrote in news:1161539089.540990.280170
@h48g2000cwc.googlegroups.com:
*snip*
I'm not clear on why it became customary in school to always
reduce fractions (is 'reduce' the right term?)
It's very clear when you're looking for the simplest form that there's
more than one way to represent a quantity. That may be why it's common
to do that.
What they don't teach (and should) is that sometimes in the real world
it's easier to leave the fraction unreduced and work with it.
Yes, that was my point. For comparison, it is much easier to
work with a common denominator. Driving it home to _always_
reduce fractions whether useful or not is the part I question.
This is also an advantage to using binary fractions instead of
decimal. It is easier to chose a base unit appropriate to the
work being done.
For fine cabinetry 1 mm is too course and its too fine for framing.
1/32" may be about right for cabinetry and 1/64" surely is. For
masonry and framing 1/8" may be about right.
You can measure or round to the nearest 2 mm or 3 mm, but
the tape or rule isn't likely to have extra long ticks every 3 mm.
No doubt the guys who have been using SI for construction all
their lives handle it fine, but I'm far from convinced that it is
better than binary fractions.
--
FF