Few weeks ago on HN there was a post about RPN calculator so I decided to get (both as an apps in form of Free42 and physical device) and learn one (for fun and giggles). It’s one of the best gadget I got in a very long time. I absolutely love it and every single time I see a calculation problem I make a simple program for it.

So for your most common use case that would be:

  00 { 18-Byte Prgm }
  01▸LBL "%INC"
  02 X<>Y
  03 ÷
  04 1
  05 -
  06 100
  07 ×
  08 END

If you do calculations often (or just are a geek who likes new toys) I thoroughly recommend one.