If you have a bit of a messy sheet, and maybe some things are numbers you’ve typed in and some are formulas and you want to be able to quickly see which ones are formulas you have 2 options.

Option 1:

Click Control + ~
This will expand all columns and show the formulas, press both keys again to go back to how it was.

Option 2:

Find & Select > Formulas
Highlights all formulas. it doesn’t show you what they are, but in a large document with many formulas,it can give you an idea of what you’re looking at. You could also color all the highlighted boxes and then all formulas would be in a different color.