Calcudoku puzzle book ✓ Lots of puzzles: more than 750 puzzles (5x5, 6x6, and 7x7) ✓ Complete solutions are included at the back of the book. ✓ Large Size: 8.5" x 11" (21.59cm x 27.94cm). "Immerse yourself in the captivating world of 'Calcudoku, ' where perplexing number puzzles and mental challenges await. This book presents a meticulously curated collection of 750 puzzles, ranging in difficulty from easy to intermediate to mind-bendingly hard, and spanning various grid sizes (5x5, 6x6, and 7x7) to ensure continuous engagement and intellectual stimulation. With its generous dimensions (8.5 x 11 inches), this book offers ample space for puzzle-solving and note-taking, guaranteeing a comfortable and immersive experience for puzzle enthusiasts of all ages. Whether you seek a quick mental diversion or a prolonged test of your cognitive abilities, 'Calcudoku puzzle book' promises hours of thrilling entertainment.