Perfect for coffee breaks, commutes or relaxing at home, this bumper collection of 300 brand new ultimate killer sudoku puzzles is guaranteed to provide you with hours of entertainment. Each puzzle is presented in a 9 x 9 grid on its own page. Printed in a portable paperback format meaning it can be taken with you on your travels or sit neatly on your bedside table.

Just when you thought it was safe to pick up a pencil Killer Su Doku is based on the original Su Doku grid, with the same rules and numbers—1 to 9—but with an added deadly twist. This time there is an element of arithmetic involved and there are few, if any, clues. The aim is to not only complete every row, column, and cube so that it contains the digits 1 to 9, but to also fill in the outlined cubes so they add up to the same number. Hints to solve the puzzle are hidden in the joined squares where only one combination of numbers applies. In the case of joined squares, if the printed number is 3, it should be 1 and 2 that go into the squares. Likewise, in the case of three joined squares, if the printed number is 6, the only combination possible is 1, 2, and 3. To add one final fiendish level, each puzzle also has a time worked out by its Japanese creators so you can try to beat the clock.

Specially compiled to provide the most deadly Su Doku challenge, this is the only volume for Su Doku enthusiasts who need a puzzle that really tests their mettle.Prepare yourself for the toughest Su Doku challenge there is. These diabolically difficult Ultimate Killer Su Doku puzzles will really put your brainpower to the test as you 'warm up' with the 100 Deadly Killer puzzles before steeling yourself to take on the 100 Extra Deadly Su Dokus. Are you ready for the challenge?Not for the faint-hearted. The puzzles use the same 9x9 grid as a regular Su Doku, but have an extra mathematical element that multiplies the challenge. The aim is not only to complete every row, column and cube so that it contains the digits 1 to 9, but also to make sure that the outlined sections, called cages, add up to the number given in each cage.Warning: Not suitable for amateur puzzlers!

The puzzles in this collection of treacherously difficult puzzles will stretch even the most advanced Su Doku enthusiast. You will need to use all of your best solving techniques to get to the end of this testing challenge. The puzzles in the collection are of the highest quality and are perfect for the advanced solver in need of a constant supply of ultra-difficult puzzles. Guaranteed to provide hours of mind-stretching entertainment.

Killer Su Doku poses an even greater challenge than the Fiendish Su Doku puzzles.Here are 100 previously unpublished puzzles for hard-core Su Doku addicts.

Killer Sudoku Puzzle Book If you like Sudoku but want an extra challenge then you will love Killer Sudoku. Killer Soduku (also known as killer su doku, sumdoku, sum doku, sumoku, addoku, or samunamupure) is like regular Sudoku, however, you must also place the numbers so that each dashed-line 'cage' adds up to the totals written in the corner of the cage. This Killer Sudoku Puzzle Book is a fun way for teens or adults to sharpen their minds and test their logic. Including 156 Puzzles of varying difficulty to keep you entertained for hours. Book Features: Loads of Puzzles 48 Easy, 54 Medium and 54 Hard Large print - 2 Puzzles per page - Plenty of Space Suitable for all Levels Beginner to Expert Perfectly Sized - 7" x 10" Premium Matte Color cover design Puzzle King Publishing: Puzzle Books for Everyone!

Sudoku puzzles, a fill-in-the-number logic square, are incredibly popular. This book provides a comprehensive Sudoku book with 1001 new puzzles organized by seven skill levels, a step-by-step guide to basic logic rules and tips to improve solving skills.