partial sum

11 LETTERS · STARTS WITH P

partial sum is a valid 11-letter word worth 14 points in Scrabble and 18 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3A1R1T1I1A1L1S1U1M3

3 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 1 + 3 =14 PTS

DOUBLE WORD → 28TRIPLE WORD → 42

MEANING

What does partial sum mean?