Fibonacci number

The Fibonacci numbers are a sequence of numbers that follows a special pattern. It's like a game where you start with two numbers, 0 and 1, and then add them together to get the next number. So the sequence goes like this: 0, 1, 1, 2, 3, 5, 8, 13, 21, and so on.

Each number is the sum of the two previous numbers. For example, 2 is the sum of 0 and 1, and 5 is the sum of 2 and 3. This pattern keeps going on and on, and each new number gets bigger and bigger.

The cool thing about these numbers is that they show up all over in the natural world. For example, the number of petals on a flower is often a Fibonacci number. The spiral pattern on the shell of a snail or a nautilus follows the Fibonacci sequence as well.

So the Fibonacci numbers are a special sequence of numbers that have a pattern of adding the two previous numbers to get the next number, and they show up in lots of places in nature.