Dan Croker has two obsessions - Sudoku and frogs. So he just had to combine his loves and make the Famous Frog Sudoku books. The Sharper Pencil Series Book contains 1,000 puzzles, 500 hard and 500 very hard. There are 4 puzzles per page and a fun and colorful cover that is sure to brighten your day. Solutions are given at the end of the book. So sharpen your pencil and get solving! More Famous Frog Sudoku series - Beach Bum Series 1 and 2, Bathroom Sudoku Series 1 & 2, Easy Series, Hard Series, Medium Series, Extra Hard Series, Brain Yoga, Giant Series, Holiday Series, Take a Break and The Travel Series.