I'm embarrassed at how long that took me to figure out.
Some more help for anyone who needs it:
- All the relevant clues are in this chapter (not previous ones).
- It has nothing to do with letters, only numbers.
- Two of the clues are one way to the answer, and the other two are a different way - but then again, you need both ways to know what order the numbers go in.
- After I solved it, I realized all I'd have had to do was multiply.