Playing the 3 x 3 grid puzzles, which revolves around the numbers from 1 to 9, is passe. The new fad that is sweeping the U.S. of A. is the 25 x 25 grid puzzle. And listen to this: The puzzle uses alphabets instead of numbers!

The Japanese challenge
This stunning puzzle is the brainchild of a Japanese master called Tetsuya Nishio. He is an expert at Suduko puzzles and a dangerous genius. He spends hours everyday, in his suburban Tokyo residence, thinking of fiendish new ways to torture our brains. Don't be fooled by his bespectacled sober looks.

The Mathematical Suduko
These higher level Suduko puzzles have the same deceivingly simple rules. You will encounter the same old digits from 1 to 9. But hold your breath, as this puzzle involves mathematics! So, hone your math skills before you even think of playing this game.

In this puzzle, you will find dotted lines that contian digits at the top of the left corner of the grid. Here, you have to fill the spaces that fall within the dotted line in such a way that their sum is equal to the number scribbled on the left corner of the grid.

Think and Play
Don't rush at the beginning. Think twice before you put the numbers in the spaces. A simple way to kickstart the puzzle, is to test the spaces and decide whether you should fill the lowest value digits first or the highest ones. Once you are able to solve this stage of the puzzle, it'll be easy for you to reach the total that is written in the top left corner.

Suppose two spaces are connected with the digit “5” in the corner. It indicates that they must be comprised of digits “2” and “3.” Or if three spaces are connected with the digit '9', it indicates that they must be comprised of '2', '3' and '4'. Here is an example to throw some light on the more complex form. Let's say that two squares are connected with the digits “15.” They must be reached with a “7” and “8.” There are many such examples. However, it is YOU who has to determine the exact place to put these numbers. This is where the actual game lies!

Are you game for this Killer Suduko?