Welcome to this superb collection of 100 circle sudoku puzzles! These puzzles all have their own solution towards the back of the book, so if you get stuck take a look there. Here are some solving tips: Place each number from 1 - 8 exactly once in each of the eight concentric circles that compose the puzzle. In addition, each number from 1 - 8 appears exactly once in each of the eight segments of the circle. Each puzzle has one solution that can be reached through logic alone. That's all there is to it!