Bob Phillips wrote:
Probably not good enough, but I'll offer it anyway.
Select a range of cells to put the numbers in. Then just start entering the
numbers, you will see the SUM totting up to the right of the status bar, it
will say SUM=nn

I suspect this is exactly what the OP wants.
But it does not seem to work for me. When I
highlight column A (by clicking on the "A"
title), I see the sum in the lower right.
But the sum disappears as soon as I click on
a cell to continue entering into the column.
Of course, I can click on the column again.
But that is not exactly the same as "seeing
the SUM tottin up" as I enter values into
column A. Am I doing something wrong?