Challenge yourself with number puzzles.

For anyone who loves the challenge of Su Doku but can solve them within minutes, you can now enjoy the extended mental workout and ultimate endurance test of a five-grid interlinked system. This is Su Doku multiplied: every column, row, and 3x3 box must contain the digits 1 to 9. Where the puzzles overlap, the rows and columns do not go beyond their usual 9x9 length but the interlocking boxes give you more clues – and more complexity.

With another 100 new Samurai puzzles to challenge you for hours, lose yourself in the four levels of this book:

• 10 Easy
• 40 Mild
• 40 Difficult
• 10 Super difficult

Even the fastest Su Doku solvers will find these ultra-complex, extended brainteasers frustrating. These are the most difficult Su Doku puzzles in The Times range. Pages: 176, Dimensions: 18.9x18.9cm