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. Already more than one million KenKen books have been sold in Japan and is a huge hit in The Times of London. Now, America can catch KenKen fever! Our first book contains 100 easy addition and subtraction KenKen puzzles with "How to Solve" instructions and an introduction by puzzlemaster Will Shortz.