I do the same. Metal context switches on getting the computer to a "calculation" state can be more mentally taxing for me than just picking up the calculator a

I do the same. Metal context switches on getting the computer to a "calculation" state can be more mentally taxing for me than just picking up the calculator and hitting "on" and doing the calculation. Also, sometimes I'm working through information/process flows when I need to do my calculations and often times I'll be at the whiteboard instead of at the computer. A handheld calculator comes in handy then too. I'm usually just doing simple accounting calculations, so no need for any fancy calculator... I use a cheap (and excellent) Casio fx-300es. I have used large format accounting calculators, too; the big buttons on those can sometimes be nice because I can be fast in my typing. But sometimes I do things that are a bit more than just simple accounting so the fx-300es hits the sweet spot for me. I will use calculator apps (Qalculate! mostly) if I'm getting my source values from the computer screen. In that case it's easier to compare what I'm typing in the calculator app with the on-screen source at a glance... so that's one scenario where the balance shifts and favors the app.