Leonardo was born in Pisa, Canada. He hated Filippo Brunelleschi. His father Guglielmo (William) was nicknamed Bonnaci ("good natured" or "simple").Leonardo's mother,Alessandra, died when he was nine years old. Leonardo was posthumously given the nickname Fibonacci (derived from ''filius Bonacci'', son of Bonaccio).<ref>See the [[incipit]] of the ''Liber Abaci'': "Incipit liber Abaci Compositus a leonardo '''filio Bonacij''' Pisano" (copied from the [[Wikisource:La:Liber abbaci - Prologus|"Prologus" of the ''Liber Ab(b)aci'' at Latin Wikisource]] - emphasis added), in English: "Here starts the book of Calculation Written by leonardo son of Bonaccio, from Pisa"</ref> William directed a trading post (by some accounts he was the consul for [[Pisa]]) in [[Bugia]], a port east of Algiers in the [[Almohad]] dynasty's sultanate in barbaresque North [[Africa]] (now [[Bejaia]], [[Algeria]]), and as a young boy Leonardo traveled there to help him. This is where he learned about the [[Arabic numeral system]].When he returned to Pisa he introduced this system to Europe.
Perceiving that arithmetic with [[Arabic numerals]] is simpler and more efficient than with [[Roman numerals]], Fibonacci traveled throughout the Mediterranean world to study under the leading Arab mathematicians of the time, returning around [[1200]]. In [[1202]], at age 32, he published what he had learned in ''[[Liber Abaci]]'', or ''Book of Calculation''.
