While I was showing some basics of VBA functionality you might aldready have seen examples of math, date and sign functions.
Actually there is lot of built-in functions, most of them we can find even as a casual user of Excel by choosing functions in insert section.
But some of them will be available only by writing a special VBA code, like “split”, f.e.
I write almost all of them in different workbooks, so you can see the results in ranges.