The Spark Sudoku stars could take many forms: pentagram (a five-arm star), hexagram (a six-arm star), septagram (a seven-arm star), and finally octagram (an eight-arm star). Contrary to the traditional square Sudoku, each row and column spans two distinct arms of the star. In this Sparks version you have to use the numbers 1 to 9. This book contains more than 260 puzzles The particular geometry of these puzzles provides a fascinating and riveting challenge.