After a calculation, if you type another digit, it appends it to the register. What the heck is the new feld below the register? It seems to hold the running result. Yeah, you can click on that. It’s also completely editable. You can position the cursor with the mouse and even insert operations between digits. It would be really cool if it would reset after pressing =. The main problem is having to manually clear after every calculation.
So, apparently I have to retrain myself to press Esc after copying instead of pressing = before. Esc is the same as the C button. Del is the same as the CA button. Pressing = or Enter sends the results to the history “tape”, but I don’t see what else it does.
Filed kcalc bug https://bugs.kde.org/show_bug.cgi?id=492518