Category: Math and trigonometry
Adds its arguments
SUM(number1,[number2],...)
Category: Lookup and reference
Returns a reference offset from a given reference
OFFSET(reference, rows, cols, [height], [width])
Category: Lookup and reference
Looks up values in a reference or array
MATCH(lookup_value, lookup_array, [match_type])
0
The formula relies on OFFSET() function because multiple values can not be returned by VLOOKUP or more accurately, VLOOKUP is unable to return range object. The thus returned values from the range is summed by SUM() formula.