Assuming you put an x or X in column B to indicate that it is
selected, then put this in C1:

=IF(B1="x", A1*1.05,A1)

and copy this down as required.

Hope this helps.

Pete

On Feb 18, 6:35*pm, juanpablo
wrote:
Hi,

I need to have an option (like a square selection box) on Column B, when the
square box is ticked, then the value adjacent needs to be multiplied by 5%,
if not selected then copy the same value.

* * * * A * * * * * * * * B * * * * * * * C
1 * * 100 * * * *(selected) * * * *105
2 * * 100 * * *(not selected) * * 100
3