You are close.
In cell A3 (directly below 1243) enter the formula, =A2
In cell A3, press Ctrl-C (or your favorite way to copy)
Using the mouse, select A2:A10 (or the bottom of the range)
NOW press F5 and click Special, then blanks, OK
Either hit Enter to copy the formula to all of those blanks OR select
Edit Paste Special Values to skip directly to the values.

That should get you started.
- John