Formulas In Place But Not Updating

Is there some security thing in Excel that is so 'rigid' that formulas from a spreadsheet (that's been downloaded from an email) will not update, even though the option to enable macros has been selected. My wife has a file that is a Stock Sheet with a straightforward arrangement of: quantities (e.g F8), prices per unit (G8), and a formula to multiply one by the other (F8*G8). The formula is visible in the formula bar. Some previous quantities are showing, and the stock value is shown, and the result of the multiplication is shown. Now if we change the quantity we expect the formula to update, but it doesn't. There is protection and the formula cells are locked, but editing is allowed (and there is no secret password for the protection), and, yet, the formulas stay showing the values that they had before the editing starts. I've used spreadsheets for many years, but never seen this. Can someone tell me what to do to make the various formulas here update as they should normally do? Thanks.

I think it will, Ron, thanks. The file is fine on my laptop. On my wife's work laptop it has this problem. Soon as I get a chance I'll confirm whether that is the solution.

Well, that was it, Ron, thanks again. Calculation Options had been set to Manual. Once altered to Automatic, everything behaved fine - formulas updated immediately on input . . . Thank you.
Lotusman