I use an HP-35s as a first stop for calculations. I also use Emacs Calc as my PC calculator. However, I still find it difficult to memorise seldom-used commands

I use an HP-35s as a first stop for calculations. I also use Emacs Calc as my PC calculator. However, I still find it difficult to memorise seldom-used commands there, so I use my HP-35s more often. Two notes: 1) I definitely prefer RPN, 2) the power management of the HP-35s is so bad that I use too many batteries for it. A good reason to overcome the memorisation problem with Emacs Calc.