Three Squares

We are what we eat, as the saying goes, but we are also how we eat, and when, and where. Our eating habits reveal as much about our society as the food on our plates, and our national identity is written in the eating schedules we follow and the customs we observe at the table and on the go. In Three Squares, food historian Abigail Carroll upends the popular understanding of our most cherished mealtime traditions, revealing that our eating habits have never been stable—far from it, in fact. The eating patterns and ideals we’ve inherited are relatively recent inventions, the products of complex social and economic forces, as well as the efforts of ambitious inventors, scientists and health gurus. Whether we’re pouring ourselves a bowl of cereal, grabbing a quick sandwich, or congregating for a family dinner, our mealtime habits are living artifacts of our collective history—and represent only the latest stage in the evolution of the American meal. Our early meals, Carroll explains, were rustic affairs, often eaten hastily, without utensils, and standing up. Only in the nineteenth century, when the Industrial Revolution upset work schedules and drastically reduced the amount of time Americans could spend on the midday meal, did the shape of our modern “three squares” emerge: quick, simple, and cold breakfasts and lunches and larger, sit-down dinners. Since evening was the only part of the day when families could come together, dinner became a ritual—as American as apple pie. But with the rise of processed foods, snacking has become faster, cheaper, and easier than ever, and many fear for the fate of the cherished family meal as a result. The story of how the simple gruel of our forefathers gave way to snack fixes and fast food, Three Squares also explains how Americans’ eating habits may change in the years to come. Only by understanding the history of the American meal can we can help determine its future.

"This book examines the patterns and beauty of positive integers by using elementary methods. It discusses some of the outstanding problems which have not been resolved even after hundreds of years of trying. A challenging problem, even for powerful computers, is factorizing integers and the book highlights some methods that are used to simplify this. We factorize integers of the type and solve the equivalent non - linear Diophantine equation where p is prime. To see if such equations have integer solutions, we use the 'Law of Quadratic Reciprocity' which is one of the most powerful results in number theory. The methods of factorization use a new arithmetic called 'clock arithmetic' which also helps in finding the last few digits of a large number without writing down all the digits. The book applies clock arithmetic to test whether a given number is prime or composite. We conclude by showing one of the great results of mathematics that a prime number which leaves a reminder of one after dividing by four can be written as the sum of two squares. However, a prime number which leaves a reminder of three after dividing by four cannot be written as the sum of two squares. Most of the results in the book are placed in an historical context"--

This book serves as an introduction to number theory at the undergraduate level, emphasizing geometric aspects of the subject. The geometric approach is exploited to explore in some depth the classical topic of quadratic forms with integer coefficients, a central topic of the book. Quadratic forms of this type in two variables have a very rich theory, developed mostly by Euler, Lagrange, Legendre, and Gauss during the period 1750–1800. In this book their approach is modernized by using the splendid visualization tool introduced by John Conway in the 1990s called the topograph of a quadratic form. Besides the intrinsic interest of quadratic forms, this theory has also served as a stepping stone for many later developments in algebra and number theory. The book is accessible to students with a basic knowledge of linear algebra and arithmetic modulo $n$. Some exposure to mathematical proofs will also be helpful. The early chapters focus on examples rather than general theorems, but theorems and their proofs play a larger role as the book progresses.

Granny squares are the perfect crochet project for beginners. They are easy to learn and quick to complete. With full instructions for all the techniques you will need at the start, followed by 25 lovely patterns to put your newly-learned skills to use, Learn to Crochet Granny Squares and Flower Motifs is the perfect book for beginners, and near-beginners who want to expand their repertoire. The repetition of stitches and patterns within granny squares is perfect for mastering the basics, and the squares can then be made up into all sorts of useful and beautiful things, from scarves and blankets to bags and cushion covers. Once you've got the hang of squares, branch out into hexagons and triangles, and then into flower motifs – the combinations of shape, colour and pattern are almost endless. Best of all, you can use up all sorts of yarn from your stash as you practise until your squares are perfect.

The natural numbers have been studied for thousands of years, yet most undergraduate textbooks present number theory as a long list of theorems with little mention of how these results were discovered or why they are important. This book emphasizes the historical development of number theory, describing methods, theorems, and proofs in the contexts in which they originated, and providing an accessible introduction to one of the most fascinating subjects in mathematics. Written in an informal style by an award-winning teacher, Number Theory covers prime numbers, Fibonacci numbers, and a host of other essential topics in number theory, while also telling the stories of the great mathematicians behind these developments, including Euclid, Carl Friedrich Gauss, and Sophie Germain. This one-of-a-kind introductory textbook features an extensive set of problems that enable students to actively reinforce and extend their understanding of the material, as well as fully worked solutions for many of these problems. It also includes helpful hints for when students are unsure of how to get started on a given problem. Uses a unique historical approach to teaching number theory Features numerous problems, helpful hints, and fully worked solutions Discusses fun topics like Pythagorean tuning in music, Sudoku puzzles, and arithmetic progressions of primes Includes an introduction to Sage, an easy-to-learn yet powerful open-source mathematics software package Ideal for undergraduate mathematics majors as well as non-math majors Digital solutions manual (available only to professors)

Number Theory Revealed: A Masterclass acquaints enthusiastic students with the “Queen of Mathematics”. The text offers a fresh take on congruences, power residues, quadratic residues, primes, and Diophantine equations and presents hot topics like cryptography, factoring, and primality testing. Students are also introduced to beautiful enlightening questions like the structure of Pascal's triangle mod p p and modern twists on traditional questions like the values represented by binary quadratic forms, the anatomy of integers, and elliptic curves. This Masterclass edition contains many additional chapters and appendices not found in Number Theory Revealed: An Introduction, highlighting beautiful developments and inspiring other subjects in mathematics (like algebra). This allows instructors to tailor a course suited to their own (and their students') interests. There are new yet accessible topics like the curvature of circles in a tiling of a circle by circles, the latest discoveries on gaps between primes, a new proof of Mordell's Theorem for congruent elliptic curves, and a discussion of the abc abc-conjecture including its proof for polynomials.