It took me a while to figure out the formula you need, and then I saw Ron's
post, but this formula will also work.
=VALUE(TEXT(A1,"#.\0\0#"))
This will work if you have only one digit after the decimal.

"Sloth" wrote:

Formatting will only change how it looks, but you could do it using
#."00"###
as the custom number format. If you actually want to change the cell you
will need a dummy column using text functions to change the number and then
copy and paste special pasting values.

"sr25" wrote:

I have the column with the data 1234.1 or 12345678.1 and I would like to
change them adding 00 zeros right after the period and the result should be
1234.001 Any help is appreciated.