calculation error inside Excel

Question

i trying to do my mothers income tax and i found excel is calculating the wrong numbers..

if you do it on a real calculator or MS calculator comes out correct but doing it it in Excel comes out wrong answer

so

A1= 8959

A2= 10637

A3 = 6408.54

calculation is

=Sum(A1/A2)*A3

Excel gives

=5397.587022

But 2 Calculators and Tax Software give

=5397.584832....

so when you round to 2 Decimals

Excel is

5397.59

and tax and real calculators is

5397.58

i know penny not important but if its a precise thing to calculate it would be

is there something else i need to do to fix this a different formula to calculate correctly

the calculation error sees to be at the *A3 part

both Calculator and Excel

correctly

Divide A1 into A2

with

0.842248754

so it happens afterwards

i did try

=sum(A1/A2*A3)

but that didnt help either