In this category of computer aided mathematics or computer algebra systems, there are also the packages sagemath, octave or scilab. octave and scilab bring there own GUI. sagemath and also python 3 or R can be used via jupyter notebook which is a kind of browser based GUI.
But these are all way to heavy programs for doing simple calculations. For that I also use `bc -l`. It has a line editor: you can write your whole calculation in one line and scroll back to previous lines to change and repeat them. Regards, Jörg.
