Excel logic

THIS EMPTY CELL IS CONSIDERED ZERO? RIGHT? YEP. THAT LOGIC CHECKS OUT; AND IF I DO CALCULATIONS WITH THESE EMPTY CELLS, THEY WILL BE 0? YEP. THAT LOGIC ALSO CHECKS OUT; THEN IT SHOULD BE POSSIBLE TO PERFORM MATH ON THIS ARRAY OF CELLS; IF THE EMPTY ONES ARE 0, THEN YES! CAN'T DO MATH ON EMPTY STRINGS YOU DUMMY! SO... LET ME PERFORM THE MATH OPERATION.