Re: Excel formula stays visible -Ck for trash in f bar in front of = sign
This happened to me too, 2011 - happy new year, the fix for me was to delete the $ sign I'd added (in front of the = in the formula bar) when pasting a formula copy into a blank cell.
I am using an Excel budget template, a helpful "
Monthly Expense Budget and Checking Account" one by Steve Chase (I'm giving you the info b/c the file name "TP102020389.." didn't relocate it for me, in case you're interested), from the Microsoft community site, but I deleted formula from 2 cells, so I copied & pasted them from the template's original cell formula to keep the template working as planned, edited them so they fit the new location, and that's when oops, visible formula in only those 2 cells and not the 30 others occurred.
So did a Google search, came here b/c Mr. Excel has been helpful in the past.
The fix for me was in correcting my error of adding a $ sign in front of the =SUM, e.g., $=SUM(Jan[[#All],[PayTotal]] in the formula bar of the pasted cells when I copied the formula bar from the original cell. (Too wordy, but there you have it.)
I'm new to Excel, but apparently trash in front of the = sign in the fx bar will make the formula visible. I tested this in the f bar of an original cell that was invisible in its cell while replying and was able to duplicate the problem.
Also of course, the formula will remain visible in the cell if you're working with it until you Tab out of it. (Mr. Excel, tks for the several icon choices!)

Time for a midnight snack. Excellllent!