Explain the following function:

SUM ( )

This function calculates the total of all the values of the specified cells and returns the result to the cell where the cell pointer is located.

Its syntax is:
=SUM(number1, number2, …….) where argument type is Number and return type is Number.

To find the sum of the cell values ranging from A1, A2, A3, …….. to An, the function will be written as:
=SUM(A1, A2, A3, ……., An)
      OR
=SUM(A1:An)