Is it everything and about everything? Don't even hope - it doesn't happen like that! No book, no library, not even the almighty Internet can find answers to all questions. Here, in this book, is about the most important thing. About what very young people who are just starting to get acquainted with the vast and beautiful world around them should know. But do not forget: the only correct answers are only in the multiplication table. And when it comes to more complex things, there are simply no definitive answers.