Change Formula

[fak119]

I have to change a great amout of formulae from a simple

=A3/A4 to either

=ROUND(A3/A4,0) or

=IF(A4=0,"",A3/A4)

Is there an easy way to change these formulae faster then individually
change each cell?

 

[MIVELD]

Are they all in the same colum

 

[fak119]

Sometimes in the same column, sometimes in the same row, sometimes they are
individual cells.