is a logic puzzle. It is a grid, partially divided by black cells into compartments. Each compartment, vertically or horizontally, must contain a straight - a set of consecutive numbers, but in any order (for example: 2-1-3-4). The aim is to fill all white cells with the numbers from 1 to N (where N is the size of the grid). No single number can repeat in any row or column. Clues in black cells remove that number as an option in that row and column, and are not part of any straight. The puzzle book contain: - 200 Puzzles - Handy 6 x 9 inch Book Layout - 2 Puzzles per Page - Ideal for Experts In the book you will find a description and examples of solutions for all puzzles. The book is for those who like logic and math problems. Decide, developing and improving.