Error in formula

[Phil Parlante]

The result of a simple sum formuls results in 0.00 when I
can add it up to a number in my head. I tried to check
the cell format but no help.....I also check the format on
the numbers I'm tring to add......... What am I doing
wrong

 

[Tim Otero]

The problem probably has to do with the way Excel (or any
program/calculator) calculates formulas...Excel will perform a calculation,
round the result to its highest level of accuracy, then perform another
calculation and round, then perform another calculation and round, and so
on. Only after all intermediate calculations are performed will it then sum
the results (if this is the way you have the sum set up---> SUM(calculation,
calculation, calculation, etc)).

You are losing accuracy in one or more of your intermediate calculations.
What, specifically, is the formula/sum you are having problems with?

tim