Straights Sudoku is a new type of brain teaser that combines the basics of Sudoku with a twist of sequential numbering. The digits 1 to 9 are still in play, appearing only once in each row and column, but now there are some black squares breaking up the action, and each consecutive group of white squares must contain numbers that make up a straight, in any order. This simple variation spices things up, so it's perfect for logic lovers looking for something unique. This book contains 504 puzzles of all levels: #1 - #84 EASY #85 - #168 MEDIUM #169 - #252 HARD #253 - #336 EXTREME #337 - #420 EXPERT #421 - #504 ELITE HAPPY SOLVING !