My experience in school (and now with my kids in school) was that there was no such thing as a group of "average" students. There's a huge variation in most grades.

Sure, you could pick the smartest kid in each class and put them in a gifted program, und give extra help to the slowest learners. But that wont help the rest of the class that still spans a huge range.

That's why I think that education should move away from the "everyone does the same thing" type.

I took some extra physics classes in high school. And guess what, in those extra classes every student got their own exercises. Because we were all at different levels and had different interests.

Why don't they do that in normal classes?