Answer:

PLUSSIGN

Answer	Crossword Clue
PLUSSIGN	Grade school operator
PLUSSIGN	Sum thing?
PLUSSIGN	Arithmetical symbol.

PLUSSIGN	Formula symbol.
PLUSSIGN	Ion symbol
PLUSSIGN	A little cross?
PLUSSIGN	Ion indicator
PLUSSIGN	Summer symbol?
PLUSSIGN	L.G.B.T.Q.I.A. follower

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.