When I went to high school, mandatory classes were basically "Choose one English, one math or science, and one Social Science course". The rest were all electives, and there were choices among those broad mandatory guidelines. I do think there's a need for age-based education in grade school, because kids develop socially, emotionally, and physically within the same general parameters (and yes, I know there will be exceptions). And young kids do need guidance and rules much more than older students, which is why the Montessorri method fails, IMO. Young children shouldn't learn the basics randomly.