You can add a zero before a number in Google Sheets and Excel using this tutorial. You need to change cell formatting or use function.

3] Add text after a set number of characters Adding text after a specific number of characters in Excel is a possibility if you know what to do.

If you have left out hyphens, Excel does include automatic cell formatting options, allowing you to uniformly add hyphens to a selection of phone numbers, social security numbers or anything else ...

Adding Percentages Using Excel. Microsoft Excel allows you to quickly add percentages to a series of numbers without performing each calculation by hand.