Though generations of schoolchildren have cursed arithmetic, the world was a much more inconvenient place without it. Before the advent of modern arithmetic in the 13th century, basic calculations ...

Pine cones. Stock-market quotations. Sunflowers. Classical architecture. Reproduction of bees. Roman poetry. What do they have in common? In one way or another, these and many more creations of nature ...

...for calculating the famous Golden Ratio, that is. But hang on, you remember the Fibonacci numbers, right? Start with 1, then add the previous number to get the next one, like so: 1, 1, 2, 3, 5, 8, ...

What do pine cones and paintings have in common? A 13th-century Italian mathematician named Leonardo of Pisa. Better known by his pen name, Fibonacci, he came up with a number sequence that keeps ...

Fibonacci retracement uses specific ratios to predict stock reversals. Key Fibonacci levels are 0%, 23.6%, 38.2%, 50%, 61.8%, and 100%. Investors use these levels for setting price goals and trading ...

In 1202 Leonardo da Pisa (aka Fibonacci) taught Western Europe how to do arithmetic with Arabic numerals. In Man of Numbers: Fibonacci's... Fibonacci's 'Numbers': The Man Behind The Math Though ...

A series of whole numbers in which each number is the sum of the two preceding ones: 1, 1, 2, 3, 5, 8, 13, etc. Fibonacci numbers are used in a variety of algorithms, including stock market analysis.