The calculator on Windows does persist a few settings, for example windows size and whether "scientific" or "standard" mode is selected. This could be saved in

The calculator on Windows does persist a few settings, for example windows size and whether "scientific" or "standard" mode is selected. This could be saved in a config file or some other storage format. Windows has a simple per-application key-value store for such settings. A relational database would be overkill and increase overall complexity.