Is there some article/book that gives a general explanation about what a child with a certain IQ range is capable of?
For example:
An 8 year old child with a range from 125-130 is cognitively at ___ level. An 8 year old child with an IQ range from 130-135 is at this ____.
Or
A child with an IQ range of 140-145 could comprehend 2 or 3 or ? years ahead of her/his age. A range of 150-155 looks like "this".

The reason I ask is this - my children always get straight A's in middle school. DD12 studies, DD10 doesn't need to. DD10 is anti-testing and has deliberately flunked a class so she doesn't need to attend (outside of school). She is also ADHD inattentive-type. Her achievement tests have all been lower than her IQ would indicate (according to the psych. who tested her). I really have no idea what she is capable of. She is also miserable at school. In the past she would tell me she was bored. Now she won't say why school is "hell on earth" (her words). I do know friendship issues are bad, but I wonder about the educational side.

Reading through Ruf's book the "5 Levels of Gifted," I observed it seems the ranges are broader than that and overlap; it also depends on other observations. Some kids score higher on different tests or at different times. But her levels information was helpful for understanding where a child might fit in a school system and what needs they might have at different ages.