Can anyone help with this query?

e.g. I want to work out how many people are working at any time in a
24 hour period. The number of people rostered on differs each day of
the week.

Monday Time No. rostered on
6.00 2
7.00 2
8.00 2
9.00 2
10.00
(and so on)


Can I add additional staff number in my 'no. rostered on column' by
just entering the number into the cell.

Say, if there were an extra 2 staff starting their 8 hour shift at 9.
am. is there a way of just typing in '2' into that cell and getting
'4'?

What I do at the moment is enter =2+2 in that cell and the 7 cells
below. This is awfully tedious when calculating staff numbers for
every hour of a whole week.

Any help on this one would be appreciated.


Thanks very much

Janev