The sum of 19 and 9 is 28.
The sum of 1 + 8 is 9.
The sum of 14 and 9 is 23.
The sum of fluorine is 9, as it has an atomic number of 9.
the sum is the answer to an addition problem e.g.4+5=9 9 is the sum
9+a.
The sum of 8, 11 and 9 is 28.
-23 is the sum of -32 and 9
135 is the sum
the sum of 1 plus 9 is 10 because 1+9
(-9)+9=0
sum involves addition so the sum of 2 and 9 equals 2+9=11