You can watch a video tutorial here.
When using Excel there will be many occasions in which you will need to create a column of numbers. If you have a table of data that has been exported from another application, you may need to add a column of numbers to create a reference for each row.
Step 1 – Insert an empty column
– Select the column where the numbers have to be inserted by clicking on the column name
– Right-click and select Insert from the context menu
Step 2 – Create the sequence
– Type the first 2 numbers for the sequence e.g. 1,2 for serial numbers
– Using the fill handle from the first cell, drag the formula to the remaining cells
OR
a) Select the cell with the formula and press Ctrl+C or choose Copy from the context menu (right-click)
b) Select the rest of the cells in the column and press Ctrl+V or choose Paste from the context menu (right-click)