When 5's map blows away, it gets caught on a piece of wood, but then blows away further when 5 and 9 approach it. However, when 5 and 9 are in the cave, 7 knows that they are in there because she sees the map caught on the piece of wood.
When 1 marks 2's number off on the calendar, it is under Thursday. 3 and 4 (also marked off) are on Friday and Saturday. Sunday's number on the next week cannot be seen, but then Monday is numbered 5, and the numbers continue from there, ending on 10 for Saturday. The following week follows the same pattern, skipping Sunday, then starting on Monday with 11, then 12, 13 before the calendar can no longer be read.