A fourth way to convert numbers saved as text back to number?

Hi - downloaded an Excel file that needed pivoting, but the numbers were saved as text, so the pivot table wouldn't add them up. Nothing new there, but the 3 ways in the Help section to get them back to being numbers didn't work. No error marker comes up, so I can't follow the links in that to convert to number. Formatting to number doesn't do the trick either. Now I've tried Paste Special with the Multiply option and that hasn't worked. Is there any other way to get these numbers recognised as numbers again?

Your cells probably contain non-printable characters.. see this article: Remove spaces from the beginning and end of a cell