To fill a series, Excel needs to know the pattern to follow. Inserting 1 and
dragging down is the same as copying. Insert 2 in A2, select A1 and A2, then
drag.

Alternately, if you have a large number of cells to fill, you can used Edit
Fill Series

Select Series in Column, Type is Linear, Step value is 1, Stop value is the
last number you want to appear. You can also choose a different step (e.g.
2) and Excel will increment subsequent cells by this number, starting with
the number you inserted in the cell to start the fill in.

"M.L" wrote:

i typed 1 on cell A1 , and drag the square around the cell but it fills the
below cells with the number 1 instead of 2,3,4,5,6,.................
Please help
Thanks