1. Select a column of numbers that you want to align by clicking on the letter of the column. For example, column C.
2. Click the Format menu and select Cells.
3. Select the Number tab in the window.
4. Select Number from the Category list.
5. Select the number of decimal places you want by clicking the up or down arrow next to the box. If you select four decimal places, for example, Excel will round off any number that has more. For example, 5.89237 will become 5.8924. Any number with fewer decimal places will be padded with zeroes. For example, 4.8 will become 4.8000.
6. Click 'OK.' Excel will now align all the numbers on the decimal.