exam paper and answer paper format

Hi,
I already sat some ACCA exams and from what I have seen so far and can tell you that:
1 – you have one exam paper which you have to give back at the end of the exam and a separate answer booklet
2- the exam paper is printed double side
3 – the answer paper have lets say around 10 pages where you have to write at the top the question you are answering to, but should you need additionnal papers that’s no problem you can get some extra pages, I did ask for some at my last exam
4 – The answer booklet is paper line
5 – no extra blank paper if offered for calculation but you can write directly on the subject, that’s what I usually do and so far it was not a problem.

Good luck for the exam!

” no extra blank paper if offered for calculation but you can write directly on the subject, that’s what I usually do and so far it was not a problem”

What does that mean? Means you CAN’T CALCULATE outside the answer sheets (like testing) before answering a question? If so, what’s the remedy for a wrong step?