multiplication in excel 2003

[Tom]

Try to multiplcate 111111111*111111111 and the result in excel is
12345678987654300. The correct result is 12345678987654321.


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http://www.microsoft.com/office/com...67c10a6&dg=microsoft.public.excel.crashesgpfs

 

[Jerry W. Lewis]

See Help for "Excel specifications and limits" subtopic "Calculation
specifications". The documented limit for Excel is 15 digits, and
1.23456789876543E+16 is the correct answer to 15 digits, as you have
noted. If you request more than 15 digits, the displayed result will be
padded with zeros, as you also have noted.

On a deeper level, Excel and almost all other general purpose software
does binary math. For its binary representations, Excel follows the
IEEE standard for double precision
http://support.microsoft.com/kb/78113
http://www.cpearson.com/excel/ rounding.htm
12345678987654321 cannot be represented exactly in IEEE double
precision; the closest approximation is 12345678987654320.
=(111111111*111111111-12345678987654300)
shows that 12345678987654320 is in fact what Excel calculated.

The characterization of this group as "Excel Application Errors" in
Microsoft's Office Discussion Groups Home is easily misinterpreted. The
standard name of the group is microsoft.public.excel.crashesgpfs, and
your post has nothing to do with Excel crashing. Your post would have
been more on topic in Worksheet Functions or General Questions.

Jerry

 

[Gary''s Student]

Oddly enough, if you want to add 12345678987654321 and 5 to get
12345678987654326, you will have to use a much, much more powerful tool than
Excel:

Try the calculator

Start > Programs > Accessories > Calculator

 

[Jerry W. Lewis]

As I noted, most general purpose software has exactly the same
limitations as Excel. As you have noted, the Windows Calculator does
does not do IEEE standard double precision.

Jerry