I suspect a lot of us would have more time in the day if it were not for Su Doku. Apparently, Sudoku was seventh of the top one hundred web searches for 2005. I can see why — it is really addictive! Similar to a crossword puzzle but totally numeric, the idea is to fill in nine rows and nine columns plus nine 3×3 matrices, all with the numbers one to nine with no duplicates. If you haven’t tried it, I highly recommend it — good brain food!

• Ready to print daily Su Doku puzzle