Today, Monday, Wanda Petronski was not in her seat. But nobody, not even Peggy and Madeline, the girls who started all the fun, noticed her absence.
-- Narrator (Wanda paragraph 1)

Importance: This statement is the first of the book and it indicates that no one even realizes that Wanda is absent. She has no friends and no one really thinks about her except when they're tormenting her about her claim that she has 100 dresses.

Nobody knew exactly why Wanda sat in that seat unless it was because she came all the way from Boggins Heights, and her feet were usually caked with dry mud that she picked up coming down the country roads.
-- Narrator (Wanda paragraph 4)

Importance: Wanda is seated in the back corner of the room where there are mostly noisy boys who don't do very well in school. It's noted that the teacher may have told her to sit there so that she'd keep all the muddy...