My kid is way smarter than me 😭

Everyone wants a little genius until they have a little genius and it’s so hard to keep him entertained and stimulated. Our son is 4 and he was severely speech delayed. He had a really hard time, saying any words that related to his needs, but at a very early age, we noticed he was grouping animals by type, and we felt like he could read as early as one and a half because he would see flashcards with the word “cow” or “circle” and point to the item or animal. Fast forward to him doing early intervention and starting school at the age of three and we quickly discovered that not only was he reading words, but full on sentences. He is also able to do addition and some very early multiplication. However, he is so hard to keep entertained. When an activity is not stimulating enough for him or is not his preferred task, it is really hard to get him to focus and do what is asked of him. We got him evaluated about three weeks ago for early access so that he could skip a grade and he was completing puzzles at a 16 to 18-year-old level. He is curious and loves to ask questions about the world around him and I just feel like he’s not being stimulated enough at school. What, if anything could I do to help bridge the gap here?