The number you are in search of is -52.
To find this, we first have to write the equation that goes along with the sentence. For this, we need to take it one term at a time.
Negative sixteen (-16) plus (+) the quotient of a number and -4 (x/-4) is (=) -3.
Now put the parenthesis together
-16 + x/-4 = -3
Now we can solve this for x.
-16 + x/-4 = 3 ---> add 16 to both sides
x/-4 = 13 ----> multiply both sides by -4
x = -52