Your child may be able to read at a 3rd grade level or higher, but may not be mature enough for the content or have the proper skills in place to actually understand the content of what he is reading. Perhaps it is not the length of the book that is bothering him, but that the book is not a good fit for him. My daughter's school used the CAFE Strategies for reading. They nicknamed it the 4 finger rule. Ask yourself the following 4 questions when reading. For each yes, you hold up a finger. If you have more then one finger down, the book is not a good fit for you and you need to pick a book at a more suitable level.
1. Comprehension: Do I understand what I am reading?
2. Accuracy: Can I read the words?
3. Fluency: Can I read accurately, with expression, and understand what I read?
4. Vocabulary: Do I understand the meaning of the words I am reading?
The skill of reading is just a visual ability to sound out grouped letters in an accurate manner. Along with reading comes comprehension, fluency, and vocabulary. For example, my daughter needs to improve on her vocabulary database, even though she is 10 and can read at a 12th grade level (accuracy) if she doesn't know what the words mean and cannot figure them out contextually (vocabulary, comprehension) then she needs to read books geared for a lower age range (currently she has the most success and enjoyment reading at a 7th or 8th grade level).
The goal shouldn't be to have your child reading at the hardest level possible, but at the most enjoyable level possible. If they excel at reading when they are little, it should continue forward as long as they continue to read, comprehend, and enjoy.
http://www.thedailycafe.com/public/1330.cfm
