# How Fibonacci Introduced The World To Numbers : NPR

To carry out their calculations, merchants in the early 13th century used an abacus or a system called finger reckoning. Commerce changed when Leonardo of Pisa â known today as Fibonacci â published the first arithmetic textbook. Mathematician Keith Devlin talks about the history of arithmetic and his new book "The Man of Numbers: Fibonacci’s Arithmetic Revolution."

http://www.npr.org/2011/08/12/139579620/how-fibonacci-introduced-the-world-to-numbers?ft=1&f=1007

## Possibly related…

1. ### The Way You Learned Math Is So Old School : NPR

If you’re a parent of a certain age, your kids’ homework can be confounding. Blame it on changes in the way children are taught math these days â which can make you feel like you’re not very good with numbers.

http://www.npr.org/2011/03/05/134277079/the-way-you-learned-math-is-so-old-school?sc=tw

2. ### The Golden Ratio

Episode three of Five Numbers, the BBC radio series presented by Simon Singh.

Divide any number in the Fibonacci sequence by the one before it, for example 55/34, or 21/13, and the answer is always close to 1.61803. This is known as the Golden Ratio, and hence Fibonacci’s Sequence is also called the Golden Sequence. Unlikely though it might seem, this series of numbers is the common factor linking rabbits, cauliflowers and snails.

3. ### The Golden Ratio

Episode three of Five Numbers, the BBC radio series presented by Simon Singh.

Divide any number in the Fibonacci sequence by the one before it, for example 55/34, or 21/13, and the answer is always close to 1.61803. This is known as the Golden Ratio, and hence Fibonacci’s Sequence is also called the Golden Sequence. Unlikely though it might seem, this series of numbers is the common factor linking rabbits, cauliflowers and snails.