Math meets sudoku in this fun, challenging puzzle craze from Japan.

KenKen is a grid-based numerical puzzle that uses basic math operations-addition, subtraction, multiplication, and division-while also challenging your logic and problem-solving skills. In a way, KenKen is like a game of pool or even chess: The more you think ahead to your next move and consider all the possible outcomes, the better you'll get . . . and the smarter you'll become!

These KenKen are getting harder! See if you have the skills to handle these high-level puzzles.