Acclaimed Japanese mathematics instructor Tetsuya Miyamoto developed KenKen in 2004 and it has since taken over the puzzling world. It takes a page from karate - another Japanese art - each title is graded by colour: White for easy, Green for medium, Brown for hard & Black Belt, for the super-tough! All in a handy-sized format, so puzzle lovers can play this addictive game wherever the mood takes them! So, you've worked your way through the easiest, for-beginners-only KenKen. The next level awaits you. Do you have what it takes to solve these 300 puzzles?