Acclaimed Japanese mathematics instructor Tetsuya Miyamoto developed KenKen in 2004 with the goal of improving his students’ math and logic skills. The result is a puzzle that’s understandable, fun, and challenging for any level of student—and most importantly encourages independent thinking, trial and error, concentration, and perseverance. But even though KenKen was born in the classroom, it was far too addictive to stay in school. The puzzle quickly became a favorite leisure activity for all ages throughout Japan and then for millions of players worldwide. In 2008, Nextoy LLC brought KenKen to the United States. Soon, it was the first daily feature since the crossword puzzle to appear in The New York Times. As its popularity grew, KenKen appeared in the Los Angeles Times, Chicago Tribune, The Times of London, Scholastic classroom magazines, and more than 100 other national US publications. An ever-growing network of teachers coast to coast praise its academic value and continue to use it in class.