Q: Is 6 a Fibonacci Number?

 A: No, the number 6 is not a Fibonacci number.

How is 6 not a Fibonacci number?

The Fibonacci Sequence is a series of numbers where you add the previous two numbers together. The sum of each is a Fibonacci number.

You start with 0 and add 1 to get the answer 1. You then add 1 + 1 to get 2. Then 2 + 1 to get 3. Then 2 + 3 to get 5, and so on.

To help you see it a little better, the numbers you add together have been color coded:


0 + 1 = 1
1 + 1 = 2
1 + 2 = 3
2 + 3 = 5
3 + 5 = 8
5 + 8 = 13


What would be the next Fibonacci number? If you answered 21, you're right. Here's how: You add 8 + 13, which equals 21. The sum of each set of numbers is a Fibonacci number. There are an infinite number of Fibonacci numbers.


So now that we have a little background on what a Fibonacci number is, let's work through it and try to see if 6 is a Fibonacci number.


Remember, we start with 0 + 1 = 1 then 1 + 1 = 2 then 1 + 2 = 3 then 2 + 3 = 5, and so on...


Long Form Fibonacci Test


0 + 1 = 1
1 + 1 = 2
1 + 2 = 3
2 + 3 = 5
3 + 5 = 8

Notice the last equation above (in red). This shows that 6 is NOT a Fibonacci number because the sum of the last equation is larger than the number 6 and the sum of the equation before it is smaller than the number 6.

  • This is just one way to find a Fibonacci number and is arguably the easiest to understand. There are many ways to calculate a Fibonacci number. Take a look at Wikipedia for more information.

More Examples

Here are the next few Fibonacci numbers for you to take a look at:

8 13 21 34 55 89

Are any of the surrounding numbers a Fibonacci number?

Let's take a look and see...

Number 4578
Fibonacci? noyesnoyes

Explore more about the number 6:


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