Question: What are the names of all instructors who advise students in the math depart sorted by total credits of the student.
SQL: SELECT T2.name FROM advisor AS T1 JOIN instructor AS T2 ON T1.i_id  =  T2.id JOIN student AS T3 ON T1.s_id  =  T3.id WHERE T3.dept_name  =  'Math' ORDER BY T3.tot_cred