SUM
Category: Mathematical Function.
Description: Adds all numbers that you specify as arguments.
Syntax: SUM(number1, number2, …)
Each argument can be a range, a cell reference, an array, a constant, a formula, or the result from another function.
If an argument is an array or reference, only numbers in that array or reference are counted.
Empty cells, logical values, or text in the array or reference are ignored.