You are welcome to have a look at my free Math Games.

When should you use the quick functions?

Every time you want to get immediate information (a "glimpse") regarding your data, or to get a general impression of it, without the need to save this information in the worksheet.

For example, you have 30 students in your classroom, and you just typed down their names.
If you want to make sure you typed down all of them, you should best use the quick function named “Count”.