On my keyboard i have some userful key like one for go to homepage, one for launch music app and others, most of them works, other not. I'm interested at "calc" and "file" key(i think the most userful), but they don't work.
Probably you need to add shortcuts for them. In System Settings >Keyboard you'll find shortcuts for variety of functions and you can change keys to use these functions.
If you want to add a custom shortcut, go to the last tab where you can create your own shortcut - you define terminal command that is performed on event of clicking for example your calc key (maybe open calculator or libre office calc)