That would be good wouldn't it. Especially if there was some way of ensuring cross class playing at breaks - maybe change classes for some things. My son is pretty average at writing (I think it is the creative process not physical as he is fairly good if he is writing about a book or non fiction) but is way above in reading and maths. My mother went to a school with 18 kids from 5 to 13 which would be good for him with the right teacher. In fact the teacher my mother remembers who taught them all sorts of obscure natural science and classics stuff would be perfect.
