Leonardo Fibonacci 
Leonardo Fibonacci was born in Pisa, Italy. His actual name is Leonardo Pisano Bigollo. Scholars don’t have an exact understanding of what “Bigollo” means but they think it may mean something along the lines of “goodfornothing.”

Leonardo Travels to North Africa to study and get a higher education. While there he learns the Arabic number system (1,2,3,10,100…).
After studying for many years in Northern Africa, Leonardo returned to Italy and wrote many of the important texts that are well known today and his best works. When he wrote the texts he introduced the new Arabic system to the European world.
Leonardo writes Liber abbaci. The book is where the Fibonacci sequence was first introduced. The sequence was brought up when Fibonacci was thinking about rabbit populations. (1, 1, 3, 5, 8, 13…)
Leonardo writes another book on geometry called Practica geometriae. The book is about how to solve geometric problems and apply them. Some examples are using similar triangle to find the height of tall buildings.
Leonardo writes a book Liber quadratorum on quadratic equations and how they could be used and solved. He proved many quadratic equation and other quadratic theories in this book. This is not is well known work however, to most scholars it is considered his best work.
Rome gives Leonardo a salary in recognition of the work he had done for the world and teaching he had done for the people in Italy, and around the world.
Leonardo dies in Rome, Italy, in the year 1250.