Infinitesimals from Leibniz to Robinson. Time to bring them back to school (Q1078156)

Ever since the formation of calculus infinitesimals have been used in teaching, whereas in theory they were avoided, even banned (at least since Weierstraß). Now, with non-standard analysis they have become ''respectable'' again. In this article the author proposes to bring infinitesimals back to school and gives some indications how this could be done. He hopes so to render calculus more attractive without loss of exactness.