How do I change a column of whole dollars to negative numbers?

cparker1976 

Enter -1 in an empty cell.

Copy that cell.

Select the column with the positive amounts.

Either click the lower half of the Paste button on the Home tab of the ribbon and select Paste Special... from the drop-down menu, or right-click anywhere in the selection, then select Paste Special... from the context menu.

Select Multiply, then click OK.

You can now clear the cell in which you entered -1.