Hi GhostUK,
I did my Stage 1 last week in Glasgow. In answer to your questions, you do indeed get given scrap paper during all the tests. The maths questions appear as part of the motivation paper - approx 5/6 out of the 40 if I remember rightly. There is no separate maths paper.
Others have already recommended this but see Nokio's post on page 22 for a guide to how many questions you should expect for each part of Stage 1 as well as timings. My tests were exactly the same and got 18 minutes for the motivation paper (although it flies by!).
Good luck!