Suppose you have a rang of cells, say A1:A20, and you want to sum only cells A1, A4 , A6, A7and A8 which are non-adjacent. You can write a formula like this:
=A1+A4+A6+A7+A8
This is OK for a few cells but for large range, it is better to write the formula as follows:
=SUM(A1,A4,A6:A8)
Which means some A1, A4 and the range A6 to A8.











