As the title says really.
My youngest son is a keen reader and is currently reading purple and gold level books without much help, he has a good understanding of what he reads too - he can answer questions, make sensible predictions and reads with great expression making the books sound exciting where appropriate etc. He's keen to try reading some chapter books and likes the sound of Flat Stanley. Are they likely to be too hard for him? I don't want to put him off by giving him books that are too hard for him but he's keen to try books with chapters.