Try =4513,77-4500 and format to 13 decimal places. You will get
13,7700000000004
which is why Excel returns False for =4513,77-4500=13,77

In problems like this, where you know where the last figure should be,
rounding can avoid surprises. Excel will return True for
=ROUND(4513,77-4500;2)=13,77

As others have noted, this is due to Excel (and almost all other computer
software) doing binary math. In binary, there are only 4 2-decimal place
fractions that can be exactly represented ( ,00 ,25 ,50 ,75 ) all others must
be approximated (just as 1/3 can only be approximated as a decimal fraction).
What you are seeing is the the unavoidable consequence of the initial binary
approximation to 4513,77. That approximation has a decimal value of
4513.77000000000043655745685100555419921875
which you don't directly see because Excel displays no more that 15 digits
of a number (as documented in Help).

Jerry

"mik" wrote:

lets try to compare the result
write to cell:
=4513,77-4500=13,77
its true or false?
(excel 2003 Sp1 professional)
do i need a coproccessor? :)


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