20-40% of kids test as gifted as gifted in your district?
In a friend's district, it's very high b/c of the demographics. Near a very large university center so most of the kids are sons/daughters of scientists, engineers, mathematicians and other Ph.D.s. Obviously in a place like that, the teachers have to differentiate in class to a much greater extent. They have methods I only dream about....math is taught at the same time so kids go to the classroom which is at his/her level, multiage classes etc.
