When I went for my interview they did have a maths test, it's really nothing to worry about. It's just stuff like working out time zones, adding, subtracting. As I remember there were only 12 questions for the maths and 15 questions for the memory test. The best advise I can give for the maths test is to use the space that they provide to do your working out. Other than that it's stuff that can be done you just need to think about it and work it out.