The New York Times Will Shortz Presents Easy to Hard KenKen: 300 Logic Puzzles That Make You Smarter 1st edition

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 Times.