If a three doesn't work, try a two. If that doesn't work either, erase it and start all over again. The secret is to always use a pencil because it is easy to correct if you make a mistake - let's do Sudoku.
This addictive game became a national phenomenon in Japan in the early 90s. A decade later, it escalated into a worldwide craze.
Many of you are familiar with the game, but maybe you don't know where it comes from.
The brainteaser was first made popular by university dropout Maki Kaji. The Japanese national stumbled upon a similar puzzle in America called the Number Place in 1984. The original version was fun, but difficult. Kaji decided to take it back to Japan, and gave it a makeover.
That was the beginning of his puzzling career. He founded his own puzzle company called Nikoli, and started publishing a quarterly magazine in Japan featuring a variety of mind-exercising puzzles.
But Sudoku is only one of the weapons in Kaji's arsenal. This time, he is bringing another brainteaser - Shikaku - to Hong Kong.