Liber Abaci

Leonardo Pisano was the first great mathematician of medievalChristian Europe.   He   played an important role in revivingancient mathematics and made great contributions of his own.   After his death in 1240, Leonardo Pisano became known as LeonardoFibonacci.                                                                     Leonardo Fibonacci was born in Pisa in about 1180, the son of a member of the government of the Republic of Pisa. When he was 12 years old, his father was made administer of Pisa's trading colony in Algeria. It was in Algeria that he was taught the art of calculating. His teacher, who remains completely unknown seemed to have imparted to him not only an excellently practical and well-rounded foundation in mathematics, but also a true scientific curiosity.           In 1202, two years after finally settling in Pisa, Fibonacciproduced his most famous book, Liber abaci (the book of theCalculator). The book consisted of four parts, and was revised byhim a quarter of a century later (in 1228). It was a thoroughtreatise on algebraic methods and problems which stronglyemphasized and advocated the introduction of the Indo-Arabicnumeral system, comprising the figures one to nine, and theinnovation of the "zephirum" the figure zero. Dealing withoperations in whole numbers systematically, he also proposed theidea of the bar (solidus) for fractions, and went on to developrules for converting fraction factors into the sum of unitfactors.     At the end of the first part of the book, he presentedtables for multiplication, prime numbers and factor numbers. Inthe second part he demonstrated mathematical applications tocommercial transactions.     In part three he gave many examples of recreationalmathematical problems, much like the type which are enjoyedtoday. Next he prepared a thesis on series from which was derived what is now called the "Fibonnaci series." The "FibonacciSequence" is also named after Fibonacci. The Fibonacci sequenceis a sequence in which...