I attended an Excel training course yesterday and looking through the
handout this morning noticed these lines in the overview:

'.......when to use '=A1+A2' and when to use '=sum(A1:A10)' and why you
should never use '=sum(A1+A2)'. I can't for the life of me remember the
trainer's explanation and can't find the answer anywhere. Could anyone help
please?

Ted