[jacobolus]

The point of learning mathematics is not to "not make mistakes". More strongly: the misconception that mathematics or mathematics education is about getting "right answers" as quickly and accurately as possible is a disaster for learning.

A calculus class should ideally be making someone think much harder than that. Calculus is about understanding the relationships involved with continuous quantities and modeling the way things move and change. It is a basic prerequisite for understanding biochemistry and statistics, essential background for understanding pharmaceuticals.