Welcome. So glad you found this forum.
You are not alone. Many/most families with gifted children have experiences very similar to what your son has been exposed to and you are describing. Often families continue teaching their gifted offspring a variety of things at home; the child simply requires/demands this, by asking many questions and/or sharing observations which may be incomplete and need further explanation and/or background.
Hopefully an idea or two in this post may be helpful...
Needs
To flourish, children need appropriate academic challenge, and intellectual peers. Unfortunately, these needs are often not met for gifted pupils in the educational system.
https://giftedissues.davidsongifted...icle_about_poor_school_f.html#Post229604Family/Friends
For gifted pupils lacking appropriate academic challenge and intellectual peers at school, family and friends may have more emphasis. Does your child have siblings, cousins, neighborhood friends, acquaintances from other interests and pursuits such as sports teams, art, dance, science, or math activities? Conversation is important, and the work of Hart & Risley documents the difference in vocabulary among very young children who have the benefit of regular conversation as compared with those lacking regular conversation.
Reading
If you have not been keeping a reading log, you may want to start one now. Some things to record may include: begin date for reading this book, end date for reading this book, title, author, fiction/non-fiction, genre, number of pages, reading level (if known), any of the child's observations, child-created alternative endings, prequels, sequels etc. Your child is at an age where they may maintain their reading log themselves.
Grades
In the USA, since the introduction of "Common Core" there have changes to grading which appear designed to provide the same grading outcomes for all pupils.
https://giftedissues.davidsongifted...245083/Grading_practices.html#Post245083Are grading rubrics used? Is it communicated to a child in advance, what the grading criteria will be?
Math
Work in mathematics may provide less opportunity for interpretation of grading elements (such as artwork background: creative design, or solid color required), and less dependence on a broad vocabulary in a particular language. Does your child enjoy math?
Advocacy
It would be helpful if you knew proactively what tests would be administered, what language they would be in, how the test results would be used, and so on.
https://giftedissues.davidsongifted...y_Advocacy_as_a_Non_Newt.html#Post183916Mindset
If your child does not know something YET, or cannot demonstrate knowledge to the teacher's or evaluator's satisfaction YET, be sure to think in terms of "...YET" so that one keeps a flexible mindset and does not develop a fixed mindset which may discourage and limit them. Celebrate effort and progress.
Value and Self-Image
Each person is unique and all persons have value, independent of their accomplishments, and deserve to be appreciated. Regardless of what one's grades are, regardless of IQ, it is important to learn and understand the structure of the system, culture, and society, in order to develop "emotional intelligence" and maximize opportunity.
