Summing takes the values in a single column and adds them together.
To SUM:
Select the column you wish to add a Sum to.
Right-click, and select Footer Calculation > Sum.
Counting returns the number of values.
To COUNT:
Select the column you wish to add a Count to.
Right-click, and select Footer Calculation> Count.
Note: At any time you wish to remove either a Sum or Count, or other Footer Calculation: follow the same steps to add it, and select the option once more to uncheck it.
