I've used excel a lot in previous classes for many assignments. It can be very useful. I will be able to use it when I teach. Mainly to keep stats for my athletes during their games.

Spreadsheets can be useful for many functions for a teacher. It can be used for the gradebook because it is very simple to use and calculate averages. It is much easier to use than a calculator because it lowers the chance of mistakes of typing something in incorrectly. If a mistake occurs, it is easier to figure out what went wrong and be able to fix it.

Storing, calculating, presenting are the three primary functions of a spreadsheet. I think those functions help many people with many tasks they have. I personally can't think of another function that the spreadsheet has.