The objective of Jigsaw Sudoku ("Geometry Sudoku", "Geometry Number Place", "Irregular Sudoku", "Kikagaku Nanpure") is to fill every row, column and sub-region with numbers 1-9 and each row, column, and sub-region must have each number exactly once.This Jigsaw Sudoku book is packed with the following features: 500 Hard Jigsaw Sudoku Puzzles Answers to every puzzle are provided. Each puzzle is guaranteed to have only one solution. Includes free bonus puzzles you can download book (Tons of Sudoku Puzzles for Adults & Seniors) Includes free bonus puzzles you can download book (Word Search With Hidden Message: 102 Puzzles for Adults and Seniors) Jigsaw Sudoku Puzzle Book is a collection of 500 Jigsaw sudoku puzzles. Part of the popular "Sudoku Puzzle Books" series, the book is designed to help keep your brain cognitively fit, flexible, and young.