You're familiar with hexadecimal, or 16x16, Sudoku. This book has a twist. There's a prominent technique used to solve Sudoku puzzles that requires the memorization of a list of characters. None of the 100 puzzles in this book require memorizing lists. There are many other devices of logic used to solve Sudokus, and you can employ them here. Don't worry - these puzzles can still be plenty difficult. For all ages. Give it a try.