November 23, 2011 - Fibonacci Day

Fibonacci numbers are defined as starting with zero and one; each following number in the sequence is formed by adding the previous two numbers.

So... 0 + 1 = 1

Therefore... the next Fibonacci number is 1. (Again!)

1 + 1 = 2

Therefore, the next Fibonacci number is 2.

1 + 2 = 3

Therefore, the next Fibonacci number is 3.

2 + 3 = 5

So the next Fibonacci number is 5.

Can you figure out the next seven Fibonacci numbers? After you do, check your answers here.  Since numbers go on to infinity, so do Fibonacci numbers! They start slow (1, 1, 2, 3, 5), but they get really, really big really quickly (the 40^th Fibonacci number is 102,334,155!).

Fibonacci numbers are associated with the Golden Ratio and spirals, and we see them in biological settings such as tree branching and flowers, arrangement of fruit spouts on pineapples and seed scales on pine cones...

Why is today Fibonacci Day? The first numbers in the sequence (other than zero) are 1, 1, 2, 3, so we celebrate the sequence on 11/23.

Find out more about Fibonacci and his sequence here and here. 

For fun...

Try writing a Word Fib Poem.