Continuity mistake: When Norma and Helen are in the salon, and they are talking about Carrie going to the prom with Tommy, Norma is getting a fancy hairdo done for the prom. But in the next gym scene, she has her plain braids and a cap on. (00:48:20)
Suggested correction: When you watch the movie leading up to that event, it's obvious that Norma is a tomboy, and is always wearing a ball cap and wearing her hair like that. It's who she is and perhaps decided after her hair was done that it didn't feel right and decided to go back to her look.
Revealing mistake: When Sue Snell wakes from her nightmare, listen carefully as her mother comforts her. At one point, she calls her Amy, which is the actress's real name (they're mother and daughter in real life).
Suggested correction: Sue's mom just keeps repeating it's all right, you never hear any name mentioned.
That's because the music is supposed to drown out any dialogue.
