quick Q about large numbers

[mark petrak]

if i was to enter a credit card number in excel it auto formats it to
this
1.23412E+15
for this number 1234123412341234

and when i enter it in and format it as a number it makes the last
number a 0 ?
1234123412341230

why?

how to fix?

 

[swatsp0p]

You need to enter this type of 'number' as text... precede with an
apostrophe ( ' ).

I assume you will NOT be doing any mathematically calculations with
this 'number'.

For numbers, Excel will only display 15 digits... it's long story that
is discussed in depth in other posts... do a search if you want more
details...

HTH

Bruce

 

[Jerry W. Lewis]

The story is not that long. Computers necessarily have finite
precision. Excel's (and almost all other software's) precision is
defined by the IEEE standard for double precision, which can represent
all 15 digit numbers, but only some 16 digit numbers. Hence MS chose to
document (see Help for "Excel specifications and limits") that they
would only display 15 digits rather than have to answer questions about
why when you enter certain 16 digit number you get back different 16
digit numbers.

Jerry

 

[swatsp0p]

Thanks for the follow up, Jerry. You told the 'story' so much bette
than I ever could have!

Cheers