Scenario: you have a list of values in a column that you want to multiply by a second value. Type the multiplier in a cell, anywhere. Click the cell and choose Edit > Copy so it’s on the Clipboard.
Now select the cells that contain the values you need to multiply. Choose Edit > Paste Special and click Multiply and click Values and click Ok. Excel replaces the values in the selected cells with the result of multiplying the values by the constant. It’s all done in situ so you don’t have to create new columns, multiply then paste the values back.
Oh, and there are options for Add, Subtract and Divide too so you can do all your math inside the current cell. Gotta love that!