SUM (Primitive Spread Function) sums cells or blocks.

SYNTAX:

SUM(value1,value2,...)

REMARKS:

Accepts up to 30 arguments. Each argument can be a cell, a cell range, a float value, or an integer value. 

EXAMPLES:

SUM(A1,B7,C11)
SUM(A1:A9)
SUM(95,89,73,87,85,76,100,96,96)=797