Excell Formula

[Belly]

I'm having difficulty remembering how to use the Excell Sum Formula. Previously I could add cells by holding down a key on my keyboard and select each separate cell in turn.

Let's say I have a column of numbers from 1 to 19 in Cells A1-A19.

I want to enter the sum of Cells A3, A5, A11 & 18 into Cell B20 and I want to select each cell in turn by clicking in the cell and NOT having to enter each cell number by hand.

Some help please

 

[Belly]

That's it, Thanks. For some unknown reason when I was clicking on cells it was showing the formula and NOT the figure in the cell. Thanks to both of you.