Getting sum of a column of numbers

Select the column or Row you want to add and the sum will be displayed at the bottom.

Numbers for Mac: Calculate values using data in table cells in a Numbers spreadsheet

you can, as previously posted, select a column and just look at the quick calculations in the bottom of the Numbers window. If you want the sum in a cell of your table, then drag the quick connect badge from the bottom of the window to the destination cell.

You will not be able to put the sum in the same column unless you open the table formatter and make sure there is at least one footer row.

another way is to select the last row of a column. Again, make sure to set at least one row as a footer row:

Then select the cell in the footer (the last row of the column) and type the formula (assuming you want to sum the values in column B):

=sum(B)