Fibonacci

Master MATHEMATICIAN of the Middle Ages

This Italian number cruncher shared a system, showed a sequence, and left a legacy.

Pisa

Bugia

Africa Europe

Leonardo of Pisa

Fibonacci was born Leonardo of Pisa in Italy in about 1170. His father was a successful MERCHANT who took his son to trading posts in north Africa. Fibonacci learned about the HinduArabic numbers when he visited Bugia, now in Algeria.

By the way… Some living creatures have the dimensions that correspond to the numbers in my sequence, including nautilus shells and chameleon tails.

Roman numbers featured complex and confusing letters of the alphabet.

Hindu-Arabic numbers made calculations simpler.

New system

On his return to Pisa, Fibonacci introduced the Hindu-Arabic number system to Europe. This counting system, which uses numerals 0 to 9, is still used today. People could see its advantages over existing Roman numbers, so the Hindu-Arabic system was adopted across the CONTINENT.

What came before…

The scratched marks on this ancient bone may have been used to represent numbers.

In ancient times, numbers were counted out using

simple tally systems.

Making marks on clay or lining up sticks and stones could represent animal herds or passing days. About 5,000 years ago, the ancient Babylonians invented one of the first number systems. These numerals were written as a series of symbols.

1 2 3

Fibbonacci is also known for a mathematical sequence of numbers in which each number is found by adding together the last two: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, and so on. These are called the FIBONACCI NUMBERS. Using this sequence for the sides of a square, a sequence of larger touching squares is formed. Then, by drawing a quarter circle between the corners of the sequence of Fibonacci squares, a spiral shape is created. Squares drawn using the Fibonacci numbers Clematis has eight petals

Buttercup has five petals Daisy has 34 petals

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1 0 2 3 13 Numbers in nature

Fibonacci’s sequence of numbers is seen all around us in nature. Many flowers have the same number of petals as a number featured in the FIBONACCI SEQUENCE. Scientists also found the sequence in plant leaves, pineapple scales, pine cones, and tree rings.

A spiral forms where a quarter circle is drawn between the squares’ corners.

What came after…

Did you know? 23 November is Fibonacci Day because in the month/date format (11/23), the numbers form the Fibonacci sequence: 1, 1, 2, 3.

The binary number system – a number system that uses only 0 and 1 – was invented by German mathematician Gottfried Leibniz in the 17th century. Today, computers store their programming as binary code, written in 0s and 1s. In 1975, geometric shapes called fractals were explained by Polish-born mathematician Benoit Mandelbrot. Sea shells are examples, producing a version of their main shape when divided down smaller.

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How he changed the world

Fibonacci’s introduction of Hindu-Arabic numbers brought mathematics to the masses. It is now a global mathematics language.