Using the same example, again and again, seems to be quite boring and without any added benefit. In some cases, a common example can be used for positive effect. Using a known example saves time, since people can draw upon older methods or algorithms to understand new ideas. In this book, the common example is the Fibonacci Sequence which starts with 0 and 1. Every next number is the sum of its two predecessors.

0, 1, 1, 2, 3, 5, 8, 13, 21,...

A well-known picture using this sequence is the Fibonacci spiral.