Ready for the ultimate test of your problem-solving skills? Then this book is just what you've been looking for! Packed with challenges that range in difficulty from complete beginner to fiendishly complex, this book offers the variety and all-out fun to keep you puzzling away for hours at a time.An ideal gift for any avid puzzle fan, these popular number games are a great way to keep your mental skills sharp while having fun at the same time. Regardless of your skill level, these 300 increasingly difficult puzzles will keep you constantly challenged, entertained, and engaged from cover to cover!