Fibonacci's Liber abaci

the long version

"Though it is now mostly known for introducing the Hindu number system and the algorithms of arithmetic that children now learn in grade school, Liber Abaci is much more: It is an encyclopaedia of thirteenth-century mathematics, both theoretical and practical. It develops the tools rigorously, establishes them with Euclidean proofs, and then shows how to apply them to all kinds of situation in business and trade, including conversion of measures and currency, allocations of profit, computation of interest, and alloying of currencies. It is rigorous mathematics, well applied, and vividly described.". "As the first translation into a modern language of the Liber Abaci, this book will be of interest not only to historians of science, but to all mathematicians and mathematics teachers interested in the origins of their methods."--BOOK JACKET.