Böcker av Yakov Perelman

This short book is a collection of simple and easily grasped tricks to speed up your mental arithmetic. If you want to master them you should realize that to be used fully they need to be approached conscientiously, not mechanically. But it pays to master them as they will enable you to do calculations in your head without error, as with written calculations.

Ce petit livre est une collection d'astuces et de techniques qui permettent d'accélérer votre calcul mental. Si vous voulez les maîtriser et les utiliser pleinement, vous devez les aborder consciencieusement et non mécaniquement. Ils vous permettront de faire les calculs mentalement, sans erreur, comme si ces derniers étaient des calculs écrits.

In this book, we look into some entertaining stories from famous authors (Leo Tolstoy, Jules Verne, Jonathan Swift, etc.) and analyze them from a scientific point of view. Using simple mathematics and physics tools, we will be able to derive new entertaining questions and answers from these stories. In some occasions, we will be able to accept or refuse the foundations underlying them.

“Mechanics for fun” is not a textbook. Instead it is a complementary book with some entertaining experiments and descriptions of some exciting natural phenomena. Its aim is to excite the reader interest in mechanics and have him engage in its study. The author has included a number of mechanics’ applications in engineering, sports, circus performances and many other unexpected areas.

This book is not a usual arithmetic book. It does not present arithmetic concepts as tedious problems that are often fruitless for everyday life. Instead, using material that is accessible to the majority of the readers, it presents multiple tricks, puzzles and problems, and explains the notions behind them in an enjoyable and entertaining manner. It is recommended for both young students (as a complement to textbooks) and adults.

"... I note that this book can be seen as an extensive physics quiz which should help the reader assessing whether he actually masters the basics of physics. However, this is not a quiz that you would find in a traditional physics exam. While seemingly simple, the questions often surprise the reader and the quick intuitive answers to these one are often wrong. The ultimate purpose of the book is to convince the reader that the domain of physics is much richer in content than many people think, and incidentally to pay attention to the misconception of a number of physical representations. This book will encourage readers to critically review and carefully check their physics knowledge..."

" Are we ever destined to travel to other planets? Or are we forever doomed to remain prisoners of Earth? The idea of interstellar travel, flying from one planet to another, is, of course, for the time being, no more than a tempting dream. We have been talking and dreaming about Leonardo da Vinci aircraft for many centuries before it became a reality. Why not admit that, over time, the dream of space travel will one day become a reality. Spaceships will rush into the universe and will move the former captives of the Earth to the Moon, the planets and even perhaps planets in other star systems... And who knows, among the current timid attempts to mentally solve this daunting problem some will be translated into reality? ..."

"Physics at Every Step" does not seek to replace physics textbooks. Its purpose is to entice the reader to consciously observe physical phenomena, including the simplest ones which we have learned to ignore in our everyday life. It allows the reader to amass evidence about physical laws, and engage in a systematic study of physics. It includes hundreds of colorful stories from the field of physics. Despite their entertaining appearance, these ones address several important and serious notions in this field.

This motley collection features more than 100 puzzles involving coin tricks, chess problems, magic squares, and a host of other intriguing scenarios. Minimal mathematical knowledge required. Includes solutions.