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''.
Leonardo became a guest of the Emperor [[Frederick II, Holy Roman Emperor|Frederick II]], who enjoyed mathematics and science too!. In [[1240]] the Republic of Pisa honoured Leonardo, under his alternative name of '''Leonardo Bigollo''',<ref>See the incipit of ''[[Flos]]'': "Incipit flos Leonardi '''bigolli''' pisani..." (quoted in the [[MS Word]] document [http://www.g4g4.com/MyCD5/SOURCES/SOURCE1.DOC ''Sources in Recreational Mathematics: An Annotated Bibliography''] by David Singmaster, [[18 March]] [[2004]] - emphasis added), in English: "Here starts 'the flower' by Leonardo the wanderer of Pisa..."<br>The basic meanings of "bigollo" appear to be "good-for-nothing" and "traveller" (so it could be translated by "vagrant", "vagabond" or "tramp"). A. F. Horadam contends a connotation of "bigollo" is "absent-minded" (see first footnote of [http://faculty.evansville.edu/ck6/bstud/fibo.html "Eight hundred years young"]), which is also one of the connotations of the English word "wandering". The translation "the wanderer" in the quote above tries to combine the various connotations of the word "bigollo" in a single English word.</ref> by granting him a salary.
