jimbols6,
If you do well in the pilapt tests but just miss the grade on the maths one then you may still get through to phase 3 but you will have to resit the maths test.
It doesn't work the other way round however. You do not get a second chance at the pilapt tests. Unless of course you are invited to re-apply in 6 months time.
Don't worry too much about the maths. Just revise the necessary techniques and you should be fine.