I finished my ATPLs in September last year and I'm with Piltdown Man - you shouldn't worry about the mathematical content of the exams. However, a good standard of English is required to understand what the questions are really asking and hence choose the right answer.
Much of the material in the ATPL syllabus has been simplified so it can be examined using multiple choice papers. As you will often have to learn and accept the JAR answer to a question, rather than the right one, not having too much background knowledge can actually work in your favour. I have a first class degree in biology and found parts of Human performance hard to accept, and I know a licensed engineer who failed the systems exam!
The bottom line is that if you work hard you'll get through!
Good luck,
Al
