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Finalist of the 2022 PROSE Awards How fast can you calculate? Would you like to be faster? This book presents the time honored tricks and tips of calculation, from a fresh perspective, to boost the speed at which you can add — whether a couple of numbers, or columns so long an accountant may faint. Find out how to subtract, multiply, divide, and find square roots more quickly. What's more, this book gives suggestions for how to find answers that are'good enough'for tricky tasks like dividing by 17. It includes brand new ways to multiply and divide irrational numbers such as pi, e, the square root of 2, and the golden ratio. It has sections devoted to ancient mathematics, and the techniques we can borrow from previous and other cultures, in order to calculate more quickly. Examples, some serious, some fun, come from everyday life or from history — like hot dog eating competitions, the Vatican's cricket team, the molecular weight of the molecule with the world's longest name, and the amount of people taken by Henry VIII to arguably history's biggest party, the Field of the Cloth of Gold. In an age of timed multiple-choice questions, the swifter you can sum, or rule out wrong answers, the better you will do. If you love to play with numbers, this book will be recreational reading. And if you ever wonder whether simple arithmetic problems can crop up in everyday life, this book provides a fresh perspective.

It is no secret that most people avoid mathematics, in large measure because elementary school teachers have never done much to motivate a love of the subject matter. In his latest book, mathematician Alfred S. Posamentier provides easily understandable, easily presentable and easily replicated tricks that one can do with mathematics. All that is required is the ability to do arithmetic, understand the very basics of algebra and geometry and have an open mind for probability. From geometrical puzzles to numerical quirks, Math Tricks will give readers that'aha!'moment they may never have received at school.

Calculatrix nos ofrece la oportunidad de cultivar zonas abandonadas de nuestro cerebro. Los ordenadores y los móviles contribuyen a que pensemos y calculemos menos, pero sabemos que nuestro cerebro es un músculo: bien entrenado puede progresar a una velocidad sorprendente... Este libro ofrece 85 trucos y estrategias para resolver operaciones en apariencia complejas. El entrenamiento que sugiere es progresivo, y su grado de dificultad, creciente. Con la ayuda de más de 500 ejercicios, estos trucos llegarán a parecernos sencillos y prácticos. Cuando digas el resultado de un problema antes de que tus amigos saquen sus calculadoras, verás cómo empiezan a considerarte de inteligencia superior. Y cuando a uno lo tratan como a alguien inteligente, tiende a comportarse inteligentemente. Christophe Nijdam está familiarizado con las cifras y el cálculo. Ha trabajado en varias instituciones bancarias, es analista financiero y preside una ONG. De prestigio reconocido en el ámbito de las finanzas, dedica también parte de su tiempo a la enseñanza. Imparte cursos sobre cómo hablar en público a estudiantes del Instituto de Estudios Políticos de París.

Discover the Mental Math Secrets to Become a Human Calculator! Schools taught you a way to do math that works when you have a pen & paper. But the same methods, takes a lot of effort when you have to do math in your head. This is because it uses a lot of your working memory (the short term memory used to complete a mental task). For example, try to mentally multiply 73,201 x 3. It might take only a few seconds to multiply the individual digits. But if you multiply right to left the way you learnt in school, you will rely on your working memory. You will use it to recall every single digit you calculate to put it back together and get your final answer. You may even find yourself calculating some digits again because you forgot one of the numbers. The difficulty increases further when you have to multiply larger numbers like 732 x 323. You will have to remember numbers across many steps. Mental arithmetic would be a lot easier to do in your head if you didn't have to remember so many numbers. In school, you learnt to write the down numbers as you calculate to free up your working memory. In mental math, there are many other ways to do the same thing. One of the tricks to free up your working memory is to calculate from left to right instead of right to left. Try multiplying 73,201 x 3 from left to right, starting from 7 x 3 and ending with 1 x 3. You will find yourself calling out the answer before you even finish the whole problem. You can use this trick to solve any math problem in the future. But we have just scratched the surface. There are many more tricks inside the book that make doing mental math as easy as reading a comic. Here is a glimpse of what you will be able to master: • Mentally add large numbers(Example: Add 8739 + 5492 in your head in seconds) • Subtract numbers fast. (Example: Mentally subtract 7520 - 4998 without writing anything down) • Multiplication tricks to multiply three-digit numbers. (Example: Multiply 323 x 123 in your head) • Square large numbers in seconds (Example: Calculate 64 x 64 faster than a calculator) • Mentally divide large numbers (Example: Divide 601324 by 73 entirely in your head) • Quickly check a calculation with 90% accuracy without re-calculating • Overcome math anxiety • Cement your mental math skills with bonus weekly training. This book only has the best techniques used by over 27 mental and Vedic math experts across the world. The techniques in this book are so simple you will wonder why nobody taught you this before. You will be able to master it, even if you have failed math in school. Imagine waking up tomorrow being able to do lightning fast math in your head. Your family & friends will look at you like you are some kind of a genius. Since you do the calculations in your head, you will acquire better mental habits in the process. So you will not just look like a genius. You will actually be one. Buy Now To Become A Human Calculator Every minute you wait to buy this book, is another minute you don't see the benefit of being good with math & numbers. Put the power of mental math to work in your life so you can quickly & easily: • make math and numbers more useful • develop better memory habits • increase concentration • develop new ways to think • and do speed math entirely in your head faster than a calculator! Get your copy today! A MUST BUY for students of Vedic Mathematics, GMAT, GRE, SAT, Case Study Interview and Case Interview.

Jacques Inaudi (1867-1950) est considéré comme l'un des plus prodigieux calculateurs mentaux de tous les temps. Il pouvait résoudre de tête très rapidement, et très précisément, des calculs arithmétiques complexes. Il fut étudié par Broca en 1880, puis par Charcot et Binet en 1892. Si le cas Inaudi a inauguré l'étude scientifique de la mémoire experte, il a orienté la psychologie française vers l'étude clinique des sujets singuliers ou extraordinaires (édition bilingue français - anglais).

Die meisten meinen, Mathematik sei die Kunst des Rechnens. Der Mathematiker Christian Hesse hält das für falsch, zumindest für zu kurz gedacht. Mathe, sagt er, sei die Kunst, Rechnen durch Denken weitgehend überflüssig zu machen. Wie das geht, und zwar i m Kopf, zeigen seine magischen Rechentricks, deren Füllhorn er hier ausbreitet. Sie machen das Rechnen so einfach, dass es keinem mehr sauer aufstößt, vielmehr spielend leichtfällt. Ist es nicht ultracool, selbst dreistellige Zahlen wie 271 in kaum sieben Sekunden im Kopf zu quadrieren? Oder das furchteinflößende Produkt 396 x 178 mit ein paar schnellen Manövern brummschädelfrei auszutüfteln? Oder die mächtige Zahl 2134215 in einer einzigen Kurzzeile durch 9 zu dividieren? Oder den Kehrwert von 19 Dezimale für Dezimale aus dem Oberstübchen herausplätschern zu lassen? Oder den Wochentag von Heiligabend, Silvester und dem eigenen Geburtstag ohne Kalender einem staunenden Publikum zu verkünden? Alles das findet sich zwischen den beiden Deckeln dieses Buches. Zudem ist es auch für all jene gedacht und gemacht, die nicht nur ihre Kopfrechenkünste beschleunigen, ja: auf Hochtouren tunen wollen, sondern sich für die Ideen hinter den Tricks interessieren, die das Verblüffende erst ermöglichen.

Mental calculations and estimations are basic, everyday skills that are essential for real-life arithmetic operations and number sense. This book presents a much needed overview and analysis of mental computation and estimation, drawing on contemporary research and empirical studies that were conducted on students, teachers and adults to cover all aspects of this complex field. Mental Computation and Estimation analyses the implications that are involved in the research, teaching and learning of mathematics and delivers effective practices that will enhance everyday learning for students. Focusing on a range of international research and studies from the School of Nature and Life Mathematics in Greece, it answers a number of important questions including: What mental calculations and estimations are, why they are important and what other mathematical concepts and cognitive behaviors are they related to? What strategies are used on mental additions, subtractions, multiplications and divisions and how are multiplication tables learned? What are the new trends in the teaching of mental calculation and estimation? An invaluable resource for all those involved in the practice and research of mathematics education, Mental Computation and Estimation will also be a useful tool for researchers, policy makers and developers of educational programs.

Do you want to double or triple the speed with which you calculate? How to Calculate Quickly is a tried and true method for helping you in the mathematics of daily life — addition, subtraction, multiplication, division, and fractions. The author can awaken for you a faculty which is surprisingly dormant in accountants, engineers, scientists, businesspeople, and others who work with figures. This is'number sense'— or the ability to recognize relations between numbers considered as whole quantities. Lack of this number sense makes it entirely possible for a scientist to be proficient in higher mathematics, but to bog down in the arithmetic of everyday life. This book teaches the necessary mathematical techniques that schools neglect to teach: Horizontal addition, left to right multiplication and division, etc. You will learn a method of multiplication so rapid that you'll be able to do products in not much more time than it would take to write the problem down on paper. This is not a collection of tricks that work in only a very few special cases, but a serious, capably planned course of basic mathematics for self-instruction. It contains over 9,000 short problems and their solutions for you to work during spare moments. Five or ten minutes spent daily on this book will, within ten weeks, give you a number sense that will double or triple your calculation speed.

How to calculate almost anything in your head.Did you know that it's easier to add and subtract from left to right, rather than the other way round?You can be taught to square a three-digit number in seconds. Learn how to perform lightning calculations in your head, discover methods of incredible memorisation and other feats of mental agility. Learn maths secrets for the real world, from shopping to calculating a restaurant tip and figuring out gambling odds (or how much you've won). Learn how to solve sudoku faster.