Let's say you have column A, B and C with 1027 numbers in each of them. To add an average column, you just go to the top of column D, type in =AVERAGE(A1:C1) and hit enter, then double-click on the lower right corner of that cell. It fills that value down to the bottom of the table. So much easier than scrolling down to the bottom and doing a fill down.
Also, when a group of cells is selected, to put the same value/formula into each of them, simply type the value or formula and hit Ctrl+Enter.
