The Hole in Thunder Plains

[Vermachtnis]

I have know idea what to do. I've added those two numbers together and the door still didn't open. How do I get threw there?
Thanks in advance.

[SeeDRankLou]

Do you have the correct door? Along with whatever math you must do, you must also do it at a certain door. It will tell you the door number.

[Squall and Rinoa]

The best advice I could give you is this - start over in the cave, and write EVERYTHING down. It's much easier that way rather than having to try and remember certain things, aspects, or numbers.

Where am I?

[SeeDRankLou]

Also, you should wear a Charm Bangle so you can have No Encounters. It will make some of the later math rather easy.