< There are 8 marks between 1 in. and 2 in. and here we can see that the distance of the line goes only up to the first mark.
Imagine this like a pizza that's divided into 8, but you only took 1 slice. That means you took only of the pizza. It is the same here on the ruler.
It's not only 1/8 though because we also have to add in the first inch. After that inch, we also have 1/8 of an inch. So in. would be your final answer. >
<u>Hope this helped! Feel free to ask anything else.</u>