Leonardo Fibonacci
Leonardo Fibonacci was an Italian mathematician who was born and lived in Pisa during the medieval times. During those times Pisa was a republic and it “was a pretty lively place, with the pepper, leather, and fur trades and so many people coming and going” (Brown 2005). It is not certain what year he was born on but, based off his mathematical writings, it is estimated to be around 1175. With Pisa being one of the greatest commercial centers with trade routes to the Mediterranean countries, it is logical that his father, a Pisan merchant named Guglielmo, wanted him to become a merchant too. He was educated at an early age beginning with his grandmother who first taught him how to read. Afterward he was taught the basic mathematics necessary to make change for purchases, convert currencies, and count supplies. In 1192 he was sent by his father to Bugia (now called Béjaïa, Algeria) to study with an Arab mathematician where he learned the concepts of “al-jabr” (Algebra) and “zephyr” (zero). Leonardo then traveled to other Mediterranean countries (to include Greece, and Egypt) in search of different forms of mathematical computations. He compared and analyzed them and noticed that Italy’s current use of Roman numerals were not as proficient as the Hindu-Arabic number system. In 1202 he wrote Liber abaci (“Book of the Abacus”) where he showed that the Indian’s number system use of decimal placement could enhance their methods of calculation. The Book of the Abacus was comprised of 15 chapters in which he presented his famous rabbit problem: Suppose that there is one pair of rabbits in an enclosure in the month of January; that these rabbits will breed another pair of rabbits in the month of February; that pairs of rabbits always breed in the second month following birth and thereafter produce one pair of rabbits monthly... (Alfred, 1963, p. 57)
This problem lead to his most famous sequence known as the Fibonacci numbers where every succeeding term is created by adding the two preceding terms together. The first twelve terms of this sequence are: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ... The Liber abaci became the most famous book of the 13th century due to the effectiveness of his problems and solutions. In time he wrote other books such as Practica Geometriae, Liber Quadratorum, and Flos. He died