The biggest, best collection of KenKen puzzles ever published!

Are you tough enough? Tkae on this collection of 200 devilishly difficult KenKen puzzles!

Perk up your mind and start your day off right with this collection of challenging KenKen puzzles. KenKen can be described simply as sudoku with basic math (addition, subtraction and/or multiplication and division). It's a fun, addictive, clever puzzle that's winning fans the world over. This edition contains 100 KenKen puzzles that use all four mathematic applications along with solving instructions and an introduction by puzzlemaster Will Shortz.

KenKen has quickly become the successor to sudoku that the world's been waiting for! KenKen became the first puzzles to be printed in the daily editions of the New York Times next to its famous crossword puzzle. This New York Times edition of KenKen contains 300 easy to hard 4x4 and 6x6 size puzzles, with "How to Solve" instructions and an introduction by puzzlemaster Will Shortz. The puzzles use all four mathematical operations and increase in difficulty, like they do in the New York Times.

Puzzle fans have fallen for KenKen and now crave more challenging puzzles. The puzzles in this edition range in size from 6x6 grids to 9x9 grids and for the first time there will also be grids without application symbols. It's the ultimate KenKen challenge! This edition will also include "How to Solve" instructions and an introduction by puzzlemaster Will Shortz. Includes: *100 very challenging KenKen puzzles *Puzzles range in size from 6x6 grids to mind-bending 9x9 grids * Introduction and solving instructions by puzzlemaster Will Shortz

The hottest craze in puzzles! From puzzlemaster and New York Times crossword editor Will Shortz comes sudoku, the new "wordless crossword" puzzle that's taking the world by storm! Once you start, you won't want to stop. These addictive puzzles are easy to explain--just fill the grid with numbers according to the few simple rules--but incredibly fun and engaging to complete. You don't need any mathematics knowledge: Just supply a pencil and an inquisitive mind. This brand-new collection features original sudoku ranging from effortlessly easy to devilishly difficult, along with an introduction from Will Shortz that explains these fascinating puzzles and how to solve them. If you're a crossword fan, a fan of logic puzzles, or just a puzzle lover in general, you will be engrossed and delighted with sudoku!

Bestselling author Dan Ariely reveals fascinating new insights into motivation—showing that the subject is far more complex than we ever imagined. Every day we work hard to motivate ourselves, the people we live with, the people who work for and do business with us. In this way, much of what we do can be defined as being “motivators.” From the boardroom to the living room, our role as motivators is complex, and the more we try to motivate partners and children, friends and coworkers, the clearer it becomes that the story of motivation is far more intricate and fascinating than we’ve assumed. Payoff investigates the true nature of motivation, our partial blindness to the way it works, and how we can bridge this gap. With studies that range from Intel to a kindergarten classroom, Ariely digs deep to find the root of motivation—how it works and how we can use this knowledge to approach important choices in our own lives. Along the way, he explores intriguing questions such as: Can giving employees bonuses harm productivity? Why is trust so crucial for successful motivation? What are our misconceptions about how to value our work? How does your sense of your mortality impact your motivation?