Adding a score counter on Harlowe 1.2.2

I'm creating a multiple choice quiz, and I'd like tell the player how they scored at the end. Ideally, I'l have different passages, depending on how the player does. So I guess the question is twofold:

1. How do I set the counter to count correct answers?
- I did find some javascript in another thread that was for Twine 1.0, but I can't get it to work in this one.

2. How do I send them to the appropriate final passage, based on their correct answers? Examples:

1-2 out of 8: "What are you even doing here?"
3-4 out of 8: "You need to do some homework."
5-6 out of 8: "Not bad, but not perfect either."
7 out of 8: "Well done!"
8 out of 8: "Aced it!"

I'm pretty new to Twine and to Javascript, so any help would be greatly appreciated.