KenKen(R) is a genuine phenomenon with more than 1.75 million books sold and regular puzzles appearing in "The New York Times, Boston Globe, Detroit Free Press, Readers Digest," and online at NYTimes.com. Invented by a teacher in Japan to help his students learn, KenKen requires simple math calculations and logic to solve its creative puzzles. Translated as "wisdom squared" in Japanese, KenKen involves addition, subtraction, multiplication and division--and with a range of difficulty levels, KenKen improves logical thinking, concentration, and perseverance. Going back to the puzzle's roots, KenKen Classroom(TM) distributes puzzles to tens of thousands of teachers--with thousands more signing on each month--in an effort to aid them in engaging students. Parents looking to help their children and teachers looking for guide those parents now have a solid resource in these first four titles of a planned series. Starting with addition, addition and subtraction, multiplication, and multiplication and division, these books each offer three sections of puzzles carefully crafted by Tetsuya Miyamoto himself to lead students into greater mastery of the puzzles, and in doing so, their own math skills and confidence. Each section ends with a certificate to celebrate its completion--a tangible way to mark the accomplishment. With education at its core, a steadily growing audience is realizing that this simple puzzle, with repeated use, can have long-lasting benefits in and out of the classroom.