If you want to find the answer to the question “Why do I need mathematics?”, this book is for you. It talks about modern applications of mathematics, without which the existence of aviation, insurance, railways, medicine, the Internet, economics is impossible... The list can go on for a long time, but it would be easier to say that the existence of the modern world as we know it is impossible. This book will be useful to a wide range of people. circle of readers, but for the most interested and prepared readers, the authors added additional information, combining them in a special appendix.