Excel:How do I exactly sum 3 rounded curency numbers
 

Excel 2000. 3 calculated payroll deductions. Each number is a percentage of
some other number. Each is rounded to the nearest cent. I need a sum that
reflects the sum of the rounded numbers. What I currently get appears to the
sum of the non rounded numbers and then the sum is rounded to cents. There
is often a penny or two difference between the Excel calculation and a manual
sum of the 3 numbers. I need the sum to reflect the total of the 3 rounded
numbers on the form.