Also sounds a lot like my son who took the WJ-III test at age 5 years 1 month. He tested very well but his current 1st grade can't fathom that he truly knows the concepts of multiplication/division/fractions/negative numbers. They are forcing the "concepts" down his throat and he is bored, restless and has completely given up on learning in school this year.
IMO, it is possible for 4 and 5 year old children to know math concepts. Just because it developmentally doesn't happen for most kids until they are older---it can happen to some kids that are younger. That is why our children score at the 99%--they are not the average kids that public schools are set up to teach.
