It takes some practice with any calculator and you will be successfull

. I allways say that in electronics you only have to remember just a few formulas, the basic ones paralel formulas, ohms law, power formulas and so on. But just for the simplicity of the parallel button thing I am also interested in a modern version of Casio fx-61f, that can include other manufacturers. I also had no luck finding an electric purpose calculator, but maybe someone had the time or luck to find one and maybe share the model or brand. I`l keep searching and if I find one I`l post a reply. Best of luck!