Put your brain through it's paces with this Brain Gym book of 1000 Very Hard Sudoku puzzles, perfect for the more experienced or those seeking a really good challenge. We exercise our bodies but our brains need a workout too! Sudoku helps keep your brain healthy and functioning well. Challenge yourself to finish all the puzzles without cheating! Solutions to all the puzzles are at the end of the book. 346 pages, 4 puzzles per page. 8.5 by 11".