Also, how giftedness presents and what someone needs academically probably has at least as much to do with personality and other traits as a number. My dd's GAI is up in the 160's but she probably would not look like she needed a ton of differentiation if she were in a good school (we homeschool). She is strong in math but doesn't like it, she is anxious and perfectionistic so she hides. And her PGness shows up in her reading and literary analysis ability. Not something that would really be noticeable in most 7th grade classrooms.
On the other hand, a mathy kid with a different set of personality traits and interests might need radical acceleration even with a number well below the PG cut. My point is that your kid's needs will be determined as much by who he is as by a number.
