excel problem

I have a collum that is my buy price, I want to ad say 10% to that, I have over 1200 items I need to do it to, I understand that I can "paste special" but what is the formula.

 

I were thinking but the dont seem to work

 

=a1+10%

 and somehow get the same formula for all of the rows

 

or =a1*110%

 

Any ideas?