Was part of the interviewer team at goetzpartners Management Consultants, did more than 30 interviews @goetzpartners for all positions (mostly Consultants, but also Managers - gp policy is that senior hires are also interviewed by more junior colleagues to check fit). Additionally interviewed 15+ people for my own strategy team and in other teams @tyntec.
Focus on case structure and approach, less math (not that it is unimportant, just hard to walk through over the phone). Very actionable advice on "traps" to look out for and which questions to ask to look smart ;-)
Also always try to "humanize" the process. It's just a job, it's just an interview and everybody's poo stinks.