Hi there,
do you mean the column width or the values in the column?
If its the former, then Gary's post is what you need.
Otherwise there are a number of ways...
You could use an array formula like this:
1 - Select the cells you want to decrease by 10%.
2 - Copy and paste to an unused section of the work book - Leave the
cells selected once you have pasted!!!
3 - Enter and = sign in the active cell and then select the cells you
want to decrease by 10% AGAIN. You should now have something like
=A1:A30 in your Activecell. Now enter * 0.9 so you have =A1:A30 * 0.9
in the active cell.
4 - Now is the magic bit! Hold down Ctrl + Shift then press Enter. All
your figures are pasted into the unused section.
5 - Copy these value and then Edit>Paste Special>Values over the
original values.
Kind regards
Bernie Russell