"Larry Jaques" wrote in message
...
On Sat, 21 Oct 2017 18:55:45 -0400, "Jim Wilkins"
wrote:


Ooooh, good one! Kudos, Mr. Wizard. Mensa pin earned.
(Was that done in your head or on your calculator?)


In my head, thanks to years of practice juggling decimal points for
slide rule solutions to chemistry and physics homework. I think the
secret is being able to remember a couple of intermediate results long
enough to combine them, a skill I slowly developed through practice.

Memorizing reciprocals helps a lot with mental division. I worked with
very smart engineers who couldn't mentally convert a waveform period
shown on a scope to its frequency, and had to ask me every time. I
used the decimal equivalents of fractions to do it.

-jsw