AddUp is a Free, Compact yet Capable Calculator. Features: Process sequences of arbitrarily complex arithmetic expressions like:

-log(1+2) * 3% + sin(4 5/6)^7

Edit previous calculations and re-calculate, cut and paste at will. Save your work to a text file (automatic or manual), restore it later. Compact single-line mode or flexible multi-line mode. Show buttons or hide them. Separately adjustable font and button sizes. Flexible snap-on screen positioning to your preferred location. Enable/disable "always on top" style. Help file included.

Adjust it to suit your preferences: Change the font. Show or hide calculator buttons used with the mouse; adjust their size as well. Switch the work area to single line mode so that it looks like a plain desk calculator. Stretch the window to any size: shrink it down to a small utility window stashed in a corner of your screen, or maximize it in multi-line edit mode for complete editing flexibility. Save the work area contents to a text file. Do this manually or automatically when you exit the program, reload it the same way to continue working where you left off. Past calculations can be modified then recalculated individually.