@MichaelP508: If you swipe up from your Home screen, tap on the search bar at the top of the screen, and manually search for the Calculator, does anything show up in the search results? If so, press and hold on the app icon and select 'Locate app' to jump to it's current location (the icon will bounce to draw your attention to it).
When you mention the Galaxy folder, do you mean the Samsung folder? If so, please follow the steps above and search for an app that would be contained within the folder, such as Smart Switch, to see if this helps.
