The book "The Concept of Number: Origin and Development" by Levi Leonard Conant is a study of the theoretical aspects of numbers and their origin. The author systematically investigates the emergence and evolution of concepts of number in the history of mankind, considering their development in different cultures and civilizations. This book is a valuable resource for anyone interested in mathematics, philosophy, or the history of science. The author helps readers to better understand the essence of numbers and their role in the development of mankind through the prism of well-known and little-known facts and theories that formed the basis of mathematical knowledge.