First of all, any formulas need to be preceded by an equals sign (=) to let
Excel know that what follows is an 'instruction' to be executed. Otherwise
the content is interpreted as a text string or -- as in this case due to the
operators you're using ("/" & "-") -- a date.
Second, by entering the numbers into your formula you're defeating the
purpose of the program. By doing it that way you have to locate & revise
every formula containing those values every time the values need to be
updated. If you store each value in a separate cell then create formulas
that refer to the cells where the required values are stored, Excel not only
does the math but also keeps the results up-to-date based on changes made to
the source (precedent) cells.
So, instead of =4-1, the program is designed for you to:
Put 4 in a cell [let's say A1],
Put 1 in cell A2, then
Put a formula in A3 that reads =A1-A2
No offense, but if you're new to the program it would be well worth your
time to go into Excel's Help from the Menu Bar. In the Help window's toolbar
click 'Contents', then follow the links in the left topics list beginning
with "Start using Excel" for starters. Also, on the main Help page there is
a link for "Discovering Microsoft Office". Click that then use the "Creating
an Excel Spreadsheet" section of the PDF... Then go back in there as time
permits & review more on how to use the program effectively.
HTH |:>)
Bob Jones
[MVP] Office:Mac