A student is adding 1 2/9 , 3 1/3 , and -4 5/6 . The first step the student performs is to find the common denominator of 9, 3, and 6. Find the student's mistake and correct it. The least common denominator of 9, 3, and 6 is 36 because you can divide 36 by all of these numbers without getting a remainder.