Just got this from my kid:
"Also, a cool birthday present would be an RPN calculator with a three-stack display, stack switch, and variable base log. Or even any (non-graphing) calculator with variable base log function (realcalc is nice, but only has log base 10 and log base e, and I don't like my graphing calculator. Also I can't use realcalc for tests)."
Does anyone even _make_ RPN calculators any more?
Or any variable base log non-graphing calculator?
And yes, I am going to tell him to suck it up and accept that
log_x y = (ln y)/(ln x)
is so easy that a variable-base log function is probably not in the cards.