Activity 10: The Fibonacci Sequence

So far you have found the Golden Ratio from rectangles and regular pentagons.

Ratios of various kinds can also be found another way – from using a number pattern. In a sequence of numbers there is usually an obvious relationship that connects one number to the next. This is sometimes found to be the ratio of one number to the previous one.

In this sequence 0, 2, 4, 6, 8, 10, 12, ......... the relationship is 'add 2' to reach the next number in the series.

Here is the pattern of Square Numbers

1
   
4
4-1=
3
9
9-4=
5
16
16-9=
7
25
25-16=
9
36
36-25=
11


In this sequence the relationship could be expressed as the

[(square root of 'n') + 1] squared


There are also other connections in some number patterns e.g. in the pattern of square numbers here you can see that the differences from one number to the next increases in the pattern of the series of odd numbers.


The Fibonacci sequence

The following number pattern is known as the Fibonacci sequence and the numbers are called the Fibonacci numbers.

1, 1, 2, 3, 5, 8, 13, 21, 34, 55,............................

Can you work out how this sequence is created?

What are the next four terms?