Left vs. right side arithmetic keys

[Peter Klein]

Thanks for the comments and the link. I’m left-handed, so I use the calculator with my right hand and write with my left. I like the newer arrangement better, even though my first HP, the HP25, used the old arrangement. Today, when I use the ‘25, I find my index finger swaying first to the right and then to the left with each arithmetic operation.

Massimo ends his posts with: "-+×÷ ↔ left is right and right is wrong"

Which reminds me of this:
“The opposite of left is right.
The opposite of right is wrong.
So anyone who’s left–
Is wrong – right?”
(Stephen Sondheim, “Anyone Can Whistle,“ 1964)

I wonder if Sondheim ever used an HP calculator…. ;-)