Final answer:
The correct function in Excel that adds all of the numbers in a range of cells is SUM.
Step-by-step explanation:
The correct function in Excel that adds all of the numbers in a range of cells is SUM. This function allows you to easily calculate the total of a set of numbers. For example, if you have a range of cells with numbers 2, 4, 6, and 8, the formula =SUM(A1:A4) will give you the result 20, which is the sum of those numbers.