Elementary school is where children learn the basics of education. High school is where they learn more specific types of subjects.
In elementary schools, all children learn the same curriculum regardless of ability. In high school, those with better abilities will take more advanced courses. Those with less, will take easier classes.
High school is where the brightest separate themselves as they prepare for college.
Here's a video explaining the merit of applying traditional (algorithmic) methods for performing long multiplication and division as opposed to new methods.
