As a parent of an only child who is currently finishing up 4th grade in the public school system, can I just give you a piece of sage advice: pick and choose your battles. This overwhelming frustration that you are feeling today is going to feel small three years from now, when by 3rd grade you feel like your gifted child is completely bored and unchallenged, especially if they start to receive negative comments on behavior (like talks to much or needs to work on self control) when they can complete the classroom assignment in 2 minutes and spend the remainder of their time trying to chat with classmates (read: distracting other students who actually do need the time to do their work). If you are leaving the school for a better situation (meaning a situation that recognizes G&T and challenges them appropriately), I would let water run under the bridge and use your experience as a lesson learned for what not to tolerate moving forward. Otherwise, you are going to burn yourself out. Good teachers who really care do make a huge difference, many public schools cannot differentiate their curriculum, but a good teacher will make an effort to help all of their students learn and grow.