"Robert Swinney" writes:

Reverse Polish Notation: Method of entering math phrases into a calculating
device. The method is somewhat arcane and difficult to follow for those
with ordinary mathematical proclivities. It is, however, "very efficient"
for those with pre-existing mathematical training. Mastering RPN provides
great feelings of satisfaction, no! pride for those that learn to use it --
errrr, make that "learn to use it well". RPN savviness yields another click
on the lock of the great Math inner sanctum. In general, those that beat
their breasts about how conversant they are with RPN, remind one of the very
tired childhood phrase, "I know something you don't know".

You may have run into RPN advocates like that.

But RPN really is better, at least for the way some people think. I own
several RPN and several algebraic calculators, and have for decades. I
use both. I normally use them in private, with nobody watching me, and
thus no one to notice which one I'm using. If I'm doing a simple
computation with one or two operations, I don't much care which type I
use. But for longer calculations, I always prefer RPN. It just fits
the way I do calculations mentally.

The problem with AE is that you have to enter the expression in the
order it's written, complete with appropriate parentheses. For complex
expressions, that means I need to *write it down before starting*. And
I do not normally do that. I calculate by performing a series of
smaller operations in their natural order, and an RPN calculator allows
me to run the calculator in parallel with my head, seeing intermediate
results as I go along. I don't start with an expression for the answer,
and I don't end up with one - I just work out the process of deriving
the answer from the inputs as I go.

So why do I own AE calculators as well? They're ubiquitous and cheap.
I'd rather lose a $10 calculator than a $100 one, so I carry the former
in my knapsack and that's what I have at work. The calculator on my
Palm supports both input modes, but I leave it set to RPN all the time.

Dave