To install:
Download the macro file umcalculator.mex and save it to your hard drive. Open this macro file or merge this macro into your existing macro file.

To use:
Jörgen said, "On my computer I have the macro launch by pressing "++" (shortkey with no prefix keys in preferences)." However, the downloaded macro is activated with the Ctrl+Shift+C hotkey. You may want to change the activation to a shortkey.

This macro can calculate + - * / and you get your calculation on a "paper strip". "C" clears the calculator, empty string returns result via keyboard to calling application.

Submitted by:
Jörgen Nydahl