Curious incident of the dog in the night-time book club help?

My group was assigned the first 20 pages of the book, "the curious incident of the dog in the night-time". We have to do a 3 person group book club (discussion) in-front of our class while our teacher marks us on what we say in the discussion. When analyzing the first 20 pages i couldn't find enough important details in the story. I need help finding important things in the first 20 pages that i can discuss in the book club. Does the dog symbolize anything? Help would be appreciated!Curious incident of the dog in the night-time book club help?
Here are some ideas about what you talk about on the first 20 pages:



Talk about the chapter numbers - how they start at two and go up as prime numbers. At first, this makes you think "what's going on? where's chapter 1?!", and then you understand that it is the boy's favourite numbers. So the chapter numbers tell you about the boy's character - he's almost obsessed with numbers.



Talk about the drawings. You don't normally see drawings like these in a book. They are the boy's drawings and he's supposed to have drawn them for you - for the reader. He tells you they can't understand most of the expressions, though they are very easy expressions. The pictures too tell you about the character of the boy - he's not very good at understanding other people. He's autistic.



Talk about how the book it supposed to be written by a boy. Try to find the things that make you think it is a boy and not a man. Does he use childish words? Does he think childish things? Does he do childish things?