The pen that stopped writing

Your book says you have already been using the scientific method without knowing it. Here is its example.

Suppose your pen stops writing. You ask yourself: "Why did my pen stop writing?"

Your first guess: the ink has finished. To test it, you open the pen and look at the refill. If the refill is empty, your guess was correct.

But suppose the refill still has ink in it. Then your first guess was wrong. You do not give up. You make another guess: perhaps the ink has dried up. Then you try something else to test this new guess.

The book says this is exactly how science works: ask a question, guess, test, and when a test says no, guess again and test again.