Number Line Problem: Identify the Value at Position 4/5

Question

What number is missing (?) from the number line below?

Let's first count how many points, including the number 1, there are on the number line.

Since there are 5 in total, we'll define the 0 point as the following fraction:

$\frac{0}{5}$

We will also define 1 as the following fraction:

$\frac{5}{5}$

Now let's fill in each point on the number line to discover which number is represented by the question mark:

$\frac{4}{5}$