Confusedcanuck, if its any consolation, I recently passed the OAA and CX CPP tests - I don't play computer games of any description and I don't own MS FS.
I've never paid to practise any such tests ... the only thing I have done to prepare in the past was to purchase a Menthal Arithmetic exercise book ... despite hating Maths at school I've managed to improve quite a bit ... certainly enough to calculate speed/distance/time questions in the CX interview without resorting to the whiteboard ...