There were 3 phone interviews and one in-person interview that lasted almost all day. The onsite interview consisted of a short math test of 10 questions. They expect all applicants to get between 8 and 10 and aren't very impressed by a perfect score. After the test you meet with 3 partners and go through case questions. 2 of the 3 cases had a correct answer and the thirds case was focused on how you thought.