adding extra digits to columns

[Guest]

I have a column of numbers (isbn for books) which should all have 10 digits.
Somewhere in the copying process some of the numbers have not been formatted
as text and have dropped the zero from the beginning of the number. I need to
add a zero to the beginning of all the nine digit numbers in the column. How
do I achieve this ?

 

[Guest]

if you want just display 10 digit: go format cell->Custome->Enter
"0000000000" to Type box
if you want to convert as text format and 10 digit:
A1: your value
B1=RIGHT("000000000"&A1,10)

 

[Guest]

If values can be of length 9 or 10 try:

=IF(LEN(A2)=10,TEXT(A2,"@"),CONCATENATE("0",A2))

then copy/paste special=>values.

HTH