JCary,

Somehow I feel that this in not really what it is that you are asking for
but with the sign in A1 and figures in B1 & C1 then:

=SUMPRODUCT((B1="+")*(B1+C1)+(A1="-")*(B1-C1)+(A1="X")*(B1*C1)+IF(C1<"",(A1="/")*(B1/C1),0))

will appear to use the sign as an operator but I would suggest you consider
building a table and using VBA to do the work.

Note that to put a single "/" into A1 you will need to preceed it with a
single quote:- '

--
HTH

Sandy

with @tiscali.co.uk


"JCary" wrote in message
...
I am a math teacher.
In creating a worksheet in cell A1 I have a + sign.
I want to be able to change that operation in cell A1.
And have the operation change in the worksheet and be understood as an
operation and not as a character.