I've tried the following simple IF test as a check on totals in a sheet where
I'm compiling accounts:

=IF(C24=SUM(C25:C50),"","!")

bizarrely, C24 and the sum of C25 to C50 are the same number, but I'm
getting a FALSE result and "!" is appearing in the check cell

In another cell i've summed C25:C50 to prove to myself that it really is the
same number - yes, it is!

the number in C24 is from another sheet in the same workbook and is in turn
the result of a SUM in that sheet - I've double checked that value and it is
correct also.

the values in each of the cells C25 to C50 are each from a a different sheet
in the same workbook

Can anyone suggest why I'm getting this false "FALSE" result?

Thanks