Although you don't get any extra marks directly for playing from memory, it does make it sound more musical - and if you really can memorize it properly -then technically safe as well, which will, in general, give you more marks.
Personally, I have never tried playing my pieces from memory in an exam, but when I practice for one I usually learn to memorize them anyways for those "just-in-cases"... in CASE I forget my book on the day, lose my spot in the music... AND so that I'm used to both ways of reading the music.
isabelsmells, (And yes everyone, I know I'm advertising for it again...) If you really aren't sure if you're pieces are complete enough to perform from memory in the exam, you can practice for it with tips from
the PracticeSpot webpage. Click the link, go to the banner on your left hand side, and click Infopedia. Then click the tab called "On practicing" beside "On Teaching". Finally go to the banner on your right hand side, and there are a list of practice tips. I would suggest you look at the pages under these categories: "Memorizing it", "Making you piece secure", and "Surviving Performance", and maybe "Polishing your piece".
I used all of the practice tips, and BOY did they help me!!! Go to that site...you might change your mind about whether or not you should memorize!!!
Question: Do they ever use grand pianos in the exams???

I have always used an upright and in my last exam they used one too...is it the right thing to expect a grand piano?