This is a simple RPN Calculator which can use on macOS.

*** Important! ***
This calculator uses reverse Polish notation for input, and the operation method is different from a normal calculator using infix notation.
If you don't know about RPN Calculator, you should learn about that before you download this app.

How to use
> Green up-arrow is ENTER button
> Stack size can be changed at Preferences.
> You can use multi calculators at same time. Please create new calculator from File Menu.
> Programs trace key operations registered in Preferences.
> You can type numbers and operators with keyboard and numeric pad.
> To use programs and scientific operators, please change to scientific mode from View menu.
> Can change number format from Preferences or View menu.