Thank you, having a look at F#, I didn't know about its unit system. As for the last point, it comes to mind because of electronics/mechanics engineering where

Thank you, having a look at F#, I didn't know about its unit system. As for the last point, it comes to mind because of electronics/mechanics engineering where the teachers always tell you to look if the numbers make sense in the context or that you should know the rough answer to a computation before hand, that is folklore that can only happen in customary units.