Sudoku

I've heard and seen sudoku many times before but got no idea what it was all about. It was like a game or something... a crossword puzzle with numbers. On my recent trip back home, I thought I should try that... something to pass the time during the flight.


Then I started to learn how to play. It was quite confusing and challenging initially but interesting and can be addictive. Now I play sudoku whenever I am bored though I am a slow player and still learning how the system work so that it can be solved quicker.
Good for concentration exercise...