> Person enters it into his calculator, gets
> the answer, and relies on it. Happens all
> the time. Not everyone speaks algebra as a
> language. Not everyone who speaks it looks
> carefully every time.

I wasn't thinking of the calculator, and how it automatically respects the order of operations. You're certainly right.

One of the problems of the keyboard is that, when you write a fraction, you don't get the choice of expressing it with a horizontal bar to separate the numerator and the denominator, instead of the diagonal virgule (/). So, writing something like 2x/1+x can't be expressed in the unambiguous way that the horizontal bar permits.

So, 2x/(1+x) it is!

Don