KENKEN is the hot new logic puzzle that makes you smarter...and it's taking the world by storm! Hailed by The New York Times puzzle guru Will Shortz as "the most addictive puzzle since sudoku," KENKEN is part logic, part maths, and wholly engrossing in a way that no other puzzle on the planet is right now.

KENKEN is available from Knight Features through an arrangement with NEXTOY, LLC. Already a big hit in The Times of London, where sudoku got its start, the KENKEN phenomenon is now spreading in the U.S.

Created in Japan by educator Tetsuya Miyamoto as a way to help students sharpen their thinking skills, it is a great tool for people of all ages looking to keep their brains nimble.

Knight Features is offering KENKEN puzzles that consist of either a 4x4 (easy) or 6x6 (challenging) grid of boxes divided into "cages," marked by bold outlines.

As in sudoku, all numbers 1 through 4 in an easy puzzle, or 1 through 6 in a challenging one, must be used without repetition in each row and column. The difference is that all numbers in each cage must combine, using the denoted math operation, to produce the target number in the top-left corner.

Nearly two million KENKEN books have already been sold internationally.