This Book is a very-simple introduction to the beautiful methods of reckoning which are generally called by the terrifying names of the Differential Calculus and The Integral Calculus. The Contents of the book are as follows . Prologue I. To deliver you from the Preliminary Terrors II. On Different Degrees of Smallness III. On Relative Growings V. Simplest Cases V. Next Stage. What to do with Constants VI. Sums, Differences, Products and Quotients VII. Successive Differentiation VIII. When Time Varies IX. Introducing a Useful Dodge X. Geometrical Meaning of Differentiation XI. Maxima and Minima XII. Curvature of Curves XIII. Other Useful Dodges XIV. On true Compound Interest and the Law of Organic Growth XV. How to deal with Sines and Cosines XVI. Partial Differentiation XVII. Integration XVIII. Integrating as the Reverse of Differentiating XIX. On Finding Areas by Integrating XX. Dodges, Pitfalls, and Triumphs XXI. Finding some Solutions Table of Standard Forms