Beginners Guide to Precalculus, Calculus and Infinitesimals

Introduction I am convinced students learn Calculus far too late.   In my view, there has never been a good reason for this. In the US, they go through this sequence of Pre-Algebra, Algebra 1, Geometry, Algebra 2, Precalculus, Calculus 1, and Calculus 2.  But is this required?   Recently I came across two books that turned...