I bought this book for my son's 5th birthday, as he's crazy about anything to do with numbers. Whilst he was able to recognise large numbers, I wasn't sure that he understood the magnitudes involved, so thought this book would help him to get his head around this concept. The book achieves this by incorporating the numbers into the story: 10 fish, 100 penguins, 1000 snowflakes, and then the surprise ending depicting 1,000,000. It's also a lovely story in its own right - the illustrations are delightful. If only maths could always be this cute!