Read the excerpt from "How to Make a Paper Airplane.”

First, fold the paper in half the long way, so that the folded paper is just as long as it was before and half as wide. Line up the edges of the paper carefully when you fold it. Then run your fingernail along the folded side to make the edge sharp. Do that every time you make a fold.

How does the reader know what order to complete these steps in?

The sequence is very well known.
The steps are numbered.
There is a picture showing the steps.
The author uses signal words.