American calculus tutoring
In fact, even in China, there are many examples of dividing a subject into elementary and advanced two-step teaching. For example, we study physics and chemistry in middle school, that is, elementary physics and elementary chemistry. When we arrived at the university, we studied general physics and general chemistry, and the basic objects we dealt with were roughly the same as those in middle schools, except that the mathematical tools we used rose from algebra, geometry and trigonometry to advanced mathematics represented by calculus.