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.

How to sum in Google Sheets Adding up columns or rows of numbers is familiar to most spreadsheet programs. Google Sheets includes a built-in function named SUM to add the total value.

Learn how to round numbers in Google Sheets using the ROUND, ROUNDUP, ROUNDDOWN, MROUND, INT, FLOO, CEILING functions.

You may need to add cells in Google Sheets if your spreadsheet needs to contain more information than it currently has room for.