Leonardo Pisano, is one of the more well known mathematicians from the Middle Ages. He was responsible for spreading the Hindu Arabic number system in to Europe, and then for the Fibonacci sequence. His father, Gugliemo Fibonacci was an Italian merchant who ran a trading post in Bugia, North Africa. He learned the Hindu Arabic number system there, and from there was inspired to learn more about the Hindu Arabic system. He traveled to Egypt, Syria, Sicily, Provence, and Greece learning from the masters of mathematics there.
After ending his travels he returned to Pisa around the year 1200AD, where he was born. There he wrote many important texts about mathematics. He revived ancient skills of mathematics, as well as making major contributions to the mathematics of the time. Fibonacci is best known for his work Liber Abaci published after he returned to Italy in 1202. Liber Abaci is what introduced Europe to Hindu Arabic numbers, and formed the base of our current number systems.
Liber Abaci was not aimed towards specifically high thinkers, or towards other mathematicians, it was aimed towards tradesman and the public to convince them of the benefits of the Hindu Arabic number systems. The book was split in to three sections, the first portion is about the Hindu Arabic numbers, the second is focused on merchants and how the new number system could assist them. These specifically relate to “price of goods, how to calculate profit on transactions, how to convert between the various currencies in use in Mediterranean countries, and problems which had originated in China. (Leonardo – Gap System)”
The third portion of Liber Abaci is what Pisano, most famously remembered as Fibonacci, is famous for. The Fibonacci sequence. The Fibonacci sequence was proposed through the following question:
A certain man put a pair of rabbits in a place surrounded on all sides by a wall. How many pairs of rabbits can be produced from that pair in a year if it is supposed that every month each pair begets a new pair which from the second month on becomes productive?
The sequence that you end up with when you work it out, is as follows:
1, 1, 2, 3, 5, 8, 13, 21, 34, 55, …
The first number was originally omitted in the first printing of Liber Abaci.
The Fibonacci sequence is found by taking the sum of the two previous numbers. So, 1+0=1, 1+1=2, 1+2=3, 2+3=5, and so on and so forth.
This sequence is also seen very frequently in nature, and in other sciences.
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