Functions are just the fancy way of saying 'all those maths things like SUM, SUBTOTAL and stuff'.

What you will find here is information about all that stuff on how to use them, just as nature Microsoft intended.

No mucking about with nesting one function within another* or other complex stuff - just the function and how to use it in its natural form.

SO, stop panicking and enjoy.

*(I may have lied a little about no nesting of functions, as I may do this from time to time, but only for a good cause)