title: Determine if a cell (value) is used in any formula
body: <p>I am trying to reverse engineer an ancient program written using VBA in excel and formulas in cells.
  There are many cells with values scattered across everywhere. Is there a fast way to check if a cell (value) is being used in another cell's forumla; or if the cell is just sitting there doing nothing so that I can delete/igonore it safely? Thanks in advance.</p>
  
  <p>I used the Ctrl+F find tool and it seems like it does work, but I just want to be sure if there is another better way.</p>