If you still cant see the formula for cells try unprotecting the sheet or the whole workbook. For example you can use F1 for help F7 for spelling and shift F3 to insert a function. While you type a function in a cell formula a pop-up menu appears.
For example to use the F12 key to change your volume you would press FNF12.
You can also click in the toolbar then choose New Formula. You can also use the menu at the top and select Edit then Copy. How to use the CONCAT Function in Excel. Thanks Neha----- Beware of scammers posting fake support numbers here.