Hi Dan,
Maths I really wouldn't worry about, it was just simple area and distance calculations, no complex formulas needed (I think you were required to calculate the volume of a cylinder and that was about the most complicated formula). I've done a few psychometric tests now and what was difficult (for myself at least) was the verbal reasoning (barely got past halfway) in comparison to previous tests. At the end of the day everyone is different, I've never really struggled with anything logical/spatial or mathematical, so know your strengths/weaknesses (and work on your weaknesses!) and you'll be better prepared IMO,
Andrew