I've just finished reading My latest puzzle love: KenKen, in which Stephen Shankland describes the latest puzzle game to migrate to the US from Japan. Well, finished reading the article and trying out a puzzle or two.
A KenKen puzzle, like Sudoku, consists of a square grid of numbers. Also like Sudoku, the rows and columns of the grid must contain one of each number available in the puzzle, with out repeating. That is where the similarities end. Unlike Sudoku, a KenKen grid can be made up of anywhere from 9 to 81 squares arranged in a 3x3 to 9x9 grid. Instead of dividing the big grid into 9 smaller square grids, you'll find the KenKen grid divided up into various odd shapes made out of any number of squares. A bold black line divides these sections, called cages. A cage may consist of two or more squares on the grid, or even just one single square. Inside each cage, you'll find a number and a mathmatical operator. (+ - x or ÷) You must use the number of squares in the cage, along with the printed number and operator in the cage, to fill in the squares. To do so, you determine which number or numbers, when combined with the given operator, result in the given number. For example:
In a cage made up of 2 squares, one of the squares has a small 3+ written in the corner. For this cage, you need to find 2 numbers that add (Because of the +) up to the number 3. In this case, hopefully you all know that the only possible combination of 2 whole numbers to add up to 3 is 1+2. So you know that these two squares will have a 1 or 2 in them.
To figure out which number goes in which square, you fall back to the old rule of no two squares in a single row or column can contain the same number. If there is already a 1 or 2 anywhere in the same row or column as the two squares you're working with, you know that the other number must be the one to go in that square.
I'm going to give a few more of these a try. In the mean time, click through to the linked article and check it out!