In The Great Gatsby, on what page does the quote "he half expected her to wander into one of his parties" appear?
In my copy of The Great Gatsby the line in question is in chapter four, page 84, almost at the end of the chapter. I have the "First Scribner Paperback Fiction Edition 1995" with the preface by Matthew Broccoli.
The line is spoken by Jordan Baker, who is asking Nick to arrange a meeting between Daisy and Gatsby. She has just finished telling Nick about the love affair between Gatsby and an eighteen-year old Daisy Fay of Louisville, Kentucky. She also tells Nick about Daisy's wedding day when she became quite drunk after receiving a letter, presumably from Gatsby.
Gatsby, of course, has built his palatial mansion on West Egg right across from the Buchanan's house on East Egg. He throws lavish parties attended by people who are basically strangers to him. He wants to impress Daisy with his wealth and he hopes, as the lines suggest, she will attend one of his parties. When she never shows up he employs the assistance of Nick, who is Daisy's cousin.
In my copy of The Great Gatsby, this quote appears on page 102 (Vintage Books, London, 2012). It is spoken by Jordan Baker, who relates to Nick the history of Daisy and Gatsby's relationship. Specifically, she talks about Gatsby's elaborate plan to win Daisy back. After building his mansion, he began hosting lavish parties in the hope that Daisy might "wander" into one of them. When she didn't, Gatsby began "casually" asking people if they knew her. Jordan happened to be one of the people Gatsby asked and she offered to help him meet with Daisy, but he rejected the offer because it was too far away.
This quote, then, sums up Gatsby's desperation to be with Daisy. He has never forgotten Daisy Buchanan and has dedicated his entire life to winning her back.