How do I add http://www. to the beginning of 500 domain names all at once

How do I add http://www. to the beginning of 500 domain names all at once

Assuming your domain names in A1

="http://www."&A1

If you have them all in a column (say A), you should be able in the column next to it type ="http://www."&A## and then copy down

A1 domain1.com ="http://www."&A1
A2 domain2.com copy above paste down

hey teethless mama assume I am the weak link in this conversation. I don't understand. If column A has a different domain name in each row 1-500, I type http://www. in column B1 then copy it and paste column A1-500 and the beginning of each cell in column A will begin with http://www. for all 500 rows in front of domain name?

if domaineroo.com is in cell A1 then you type ="http://www."&A1 in cell B1 and copy and paste it down to B500.