The principles of algebra were founded by al-Khwarizmi many centuries ago, in a time when mankind had no calculators, computers, or electronic gadgets. There were no telephones and the only means of communication was by messenger on horseback and boat. Yet the usefulness of algebra in almost every walk of life involving numbers has ensured not only its survival but also its continued development right up to the present day. Armchair Algebra is a collection of problems, some with a very practical application, others designed as purely theoretical puzzles, that will offer something of interest to everyone. Each section is written in an easy-to-follow format and guides the reader progressively through this fascinating subject. Understand algebra, and all other branches of mathematics and arithmetic will suddenly open up in front of you. Armchair Algebra starts with a section of Algebra Basics, which provides topic-specific introductions to all of the basic theories and skills you’ll need for the exercises contained throughout the book. Each subsequent section consists of a combination of exercises, profiles, and background information on a range of fascinating subjects.

Part of the Armchair series, Armchair Chemistry is a quick refresher course in how we survey of the science. It explains how we evolved from believing in alchemy to discovering modern chemical equations and goes into detail about the lives of the scientists that uncovered them. Fascinating and interactive, this is ideal for the student brushing up on a subject or for as a clear and accessible companion for beginner's and experts alike. It contains explanations of different chemical concepts, as well as profiles of key scientists and and their discoveries. It contains clear and concise explanations of different chemical concepts, as well as profiles of key scientists and their discoveries. A unique feature of the book is its simple, step-by-step exercises. Some of these have everyday applications, others are theoretical puzzles, but all are designed to challenge you and test your newly acquired knowledge. The perfect companion for beginners and experts alike, Armchair Chemistry does not assume prior knowledge of the subject. It conveys the basic elements of chemistry in a way that is clear and accessible, no matter your level of ability.