Micrsoft has just posted a very nice article to help users add and count contents within a spreadsheet.
Although most people are familiar with basic excel formulas, not everyone has had the need or opportunity to use more complex formulas, that count the number of items in a list, etc....
The is very nice, demonstrating how to count the items in a list, count only the items that are blank (or not), counting unique items only and applying your own criteria.
Knowing the number of items in a list and being able to add them together is essential for basic statistical analysis. I recommend a quick browse through the article, even for experienced excel users.
Have a great day,