This book discusses the simple internal calculator processes (called algorithms or programs) that produce these results and similar. Although the text focuses on the calculator keys that compute power, roots, logarithms, and trigonometric functions, are also given insight into a simple program, conversion between decimal and binary numbering, and most importantly, the structure of our numbering system. However, high school algebra and a minimum understanding of programming (provided by this text) supply enough background to understand the algorithm.