We use spreadsheets in our class room to keep organized and keep records of our students grades example the grade book. We simply write in the assignment in the cells beginning the columns, then in the first cells beginning the rows we put the students name and then whatever grade they make for whatever assignment we put in the grade in the row and column that it goes in. This is a huge advantage over a calculator because you can easily add up the average with just typing in a formula instead of having to go and punch in the grades into the calculator and coming up the with average. Plus if you want to see your students progress over each six weeks you could make a graph over it and see if the student has improved or not improved.
The three primary functions of a spreadsheet is to store, calculate, and present information. This pretty much covers what a spreadsheat does. By storing you keep records of assingments and keep them organized, by calculating you find the average out of your students grades or for whatever other purpose you want to use it, and by presenting it you use the graphs to present the work of whatever it is you want to present.
Jonassen, D., Howland, J., Marra, R. M., & Crismond, D. (2008). Meaningful Learning With Technology. Upper Saddle River, New Jersey: Pearson Prentice Hall.