#Antique #calculators typically degrade through lack of use. Oil/grease gets stiff, dust/dirt takes over. My solution is repeat the simple calculations I usually perform in my head or on my computer on one (or more) of my calculators to exercise them.
This has the side-effect of reminding me how to use each of these calculators, as they all have different methods to perform basic arithmetic, none of which are intuitive.
