why do long numbers get rounded?

[Guest]

long numbers are the bane of my existence, but my business uses them every
day. for example, type in 1234567891234567 - and Excel will convert it to
1234567891234560! 12345678912345678 becomes 12345678912345600, and on and
on, and there's no way of converting them back that i've been able to figure
out. formatting the cell is no help either - this helps in general and
number formats. any idea how i can fix this and make excel useful again?

 

[Lady Layla]

Excel only recognizes 15 significant digits Are the long numbers truly numbers
with a need for mathmatical intervention or are numbers serving in a text
capacity?


: long numbers are the bane of my existence, but my business uses them every
: day. for example, type in 1234567891234567 - and Excel will convert it to
: 1234567891234560! 12345678912345678 becomes 12345678912345600, and on and
: on, and there's no way of converting them back that i've been able to figure
: out. formatting the cell is no help either - this helps in general and
: number formats. any idea how i can fix this and make excel useful again?

 

[David McRitchie]

actually they are probably truncated, though since they are binary
it might be hard to tell what that comes out to in decimal.

Numbers in Excel are limited to 15 significant digits, hardly something
that is going to make much difference in most scientific circles.

Numbers in Excel are Floating Point, it is the standard because all the
people designing spreadsheets said that it was. Floating point registers
are a lot cheaper and faster than decimal processing. Computer languages
have a limitation on how many digits they will handle arithmetically and
Excel is not an exception to that.

The major complaints come from those who try to enter 16 digit credit card
numbers -- format them as text first as they are ID, not numbers to be
processed arithmetically.

 

[Guest]

Of course, you can always just type an apostrophe before the number and Excel
will show all digits. This simply forces Excel to store it as a text value.
If you're pasting the value from some other source, format the destination
cell(s) as text first. (Formatting doesn't help after the fact, because the
data type is already established. A cell's data type and its format are very
different things.)