Excel offers a few ways you can apply a formula to an entire column or row, instead of typing or copying each cell separately.
We are going to use the following example.
The formula in cell C2 sums cell A2 and B2.
Copy a formula by dragging
The first method is called AutoFill. To use it, move your cursor over the green square in the bottom right corner of cell C2 and drag it to cell C11.
Copy a formula by double-clicking
Dragging formula is fine unless you deal with a huge number of rows.
In this case, you can double-click the green square and formulas will be filled to the end of the column.
The only problem with this approach is that if you have a blank cell on the way, the fill stops before this cell.
In this case, you can create a table (Ctrl + T). Now, if you double-click the triangle all cells will be filled, and the ones without numbers to sum will return 0.
Fill down a single cell
So far, we copied the entire column, but you can do it for a single cell.
The first way to do it is of course, by dragging a square one cell down.
You can also move your cursor under the formula and navigate to Home >> Editing >> Fill >> Down.
Performing so many steps is not really practical, it much better to remember a keyboard shortcut. You can copy down a cell using Ctrl + D.