How do I copy a series of numbers in Excel?

To copy a series of numbers in Excel, use the fill handle.

Here's how:

1. Select the cell containing the number you want to copy.
2. Hover your mouse over the bottom right corner of the selected cell. Your cursor will change to a black plus sign (+). This is the fill handle.
3. Click and drag the fill handle down or across the cells where you want to copy the number.
4. Release the mouse button. The original number will be copied to all the selected cells.

Example:

If cell A1 contains the number "5", dragging the fill handle from A1 to A5 will result in cells A2, A3, A4, and A5 also containing the number "5".

This method is best for duplicating a single value. If you need to create a series of incrementing numbers (e.g., 1, 2, 3, 4...), you'll need to either use the fill handle with Excel's series feature or enter the first two numbers to establish the pattern before using the fill handle.