How to.....with Microsoft Excel?

How would I do a sum total of a couple columns, placing the sum in a third, adjacent column with Microsoft Excel?





Thanks to anyone who can help. :}How to.....with Microsoft Excel?
If you want the sums of A, B and C in D, for lots of rows:





In D1, =SUM(A1+B1+C1)





Then go to the lower right corner of D1 (the cursor will turn into a black +) and double-click. The formula will be autofilled down as far as column C is filled - with the correct formula for each row.How to.....with Microsoft Excel?
=SUM(A1:A50,B10:B20)





You could put that formula in ant cell in column C or where ever.
draw three colums and then name them..