Hi Mike,

Excel's limitation of 15 significant digits is not caused by Excel or
Microsoft. All other spreadsheet programs, including Lotus 123 and Corel
Quattro Pro, have the same limitation. The limitation is enforced by the
microprocessor. All Intel, Intel-compatible, Macintosh, and UNIX
microprocessors have the same limitation.

The 15 significant digit limitation is part of an industry standard called
"IEEE 754", which was created to achieve faster processing by sacrificing
precision. IEEE 754 was ratified in 1985, by which time it had already
become a de facto standard.

To do math in Excel on numbers with arbitrarily large numbers of significant
digits, you'll need an Excel add-in that does its own high-precision
arithmetic in software and ignores IEEE 754. That's slower than using the
microprocessor to do the arithmetic, though maybe not as slow as
microprocessors that were popular in 1985 when IEEE 754 was ratified.

My Excel add-in xlPrecision 2.0 allows up to 32,767 significant digits. The
worksheet functions it provides do all arithmetic in software and ignore
IEEE 754. You can download the free edition here and use it as long as you
wish:

http://PrecisionCalc.com


Good Luck,

Greg Lovern
http://PrecisionCalc.com
Eliminate Hidden Spreadsheet Errors



"Mike One" wrote in message
...
I find this ridiculous and a bug. It will really screw up your excel sheet
when you are using CC numbers (which I found the issue with). I'm
currently
using the 'quote' workaround but I can't believe a spreadsheet programme
would just do this without warning. Microsoft - BAD DOG!

"Mike One" wrote:

Format a cell as number and set decimal places to 0.

Then enter 1818181818181818 in a cell and hit enter...

Excel then CHANGES to the number to:

1818181818181810 ???? WHAT ???

This can't be right can it ??, what am I missing ?