As I told you above, you don't need an array in this exercise.
You should get rid of it because it seems to confuse you, and it's not required in the instructions to pass the exercise.
Now that your array is gone (since you don't need it), you don't need to call
Great. Now, the instructions say:
Define your own method,
that accepts a single parameter and yields to a block. Then call it
with a block that multiplies the number parameter by 2. You can double
any number you like!
So, you defined your method
double, so far so good. Your method accepts a single parameter, ok. Your method yields, no problem.
But where is the part I put in bold? Where did you call your method? Since you didn't call it, you obviously never gave it a block, even less an argument. That's what's expected of you, and that's what the syntax provided in the hint describes.