Continuity mistake: When Cady is trying to get out of going to Madison, watch the level of her Dad's glass of water. From the first shot of the table to when he picks it up whilst saying "I think Cady's old enough..." the water level lowers. (00:52:50)
Continuity mistake: When Cady is confronted by Aaron in her room, she puts her drink on a pile of CDs, the CD pile starts to fall in the background as there is a shot of him, a split second later the cup is on the table next to the CDs, and the CDs are piled differently. (00:58:40)
Continuity mistake: As Regina is about to write the things about herself in the Burn Book, as she flips to a new page we can briefly see the page about Miss Norbury on it, and it doesn't say "Ms Norbury is a pusher. A sad old drug pusher," but later on when Miss Norbury picks up a photocopied sheet of the same page, it does have the previous comments written in. (01:00:05 - 01:03:55)
Continuity mistake: Before Regina starts writing the nasty things about herself in the "Burn Book", there is a red pen on the floor near the book. The next shot in a closeup of the book the pen has now moved to being right next to the book. (01:00:05)
Continuity mistake: When Regina becomes angry, and writes the horrible message in the burn book about herself to frame Cady and the others, the handwriting changes between shots. Look at "DO NOT TRUST HER" and "She is a fugly slut." - The handwriting changes noticeably, and "fugly slut" changes a lot - she writes it so the "g" and "y" have curled ends, yet it cuts to her sticking her photo in, and the ends to the tails on the "g" and "y" are straight. The line under "fugly slut," and the exclamation mark both change too. (01:00:15 - 01:00:45)
Continuity mistake: When we see the first shot of Regina throw a pile of Burn Book sheets to the floor, they fall and all spread out. Then she sticks a sheet about Trang Pak up and then in the next shot as she continues to walk, the sheets she first dropped behind her on the floor are all much closer together in a different position. (01:02:35)
Continuity mistake: Cady breaks up her Spring Fling tiara that she receives. On stage, she breaks it up into many pieces and throws them out into the crowds; it is clear that the amount we see being thrown into the crowds is a major amount of pieces - almost too much from just one tiara. However then when she leaves the stage, we see her holding approximately half of the tiara still. This would not be possible from the aforementioned amount that Cady has already snapped off and thrown into the crowd. (01:25:15)
Continuity mistake: When the Mathletes are entering the spring fling, Cady's hands are in her jacket. When the shot changes, her hands are out of her jacket and can be seen. (01:26:20)
Continuity mistake: When Mr. Duvall takes the mic after Cady's speech at the Spring Fling, he steps with his left shoulder forward. In the next shot, his right shoulder is forward. (01:29:25)
Continuity mistake: During the dance scene, the captain of the Mathletes goes up to Cady's friend Janice and starts dancing with her. At first she's smiling, but the next shot shows her with a straight face. (01:31:15)
Continuity mistake: In the scene where Cady is chasing Damien's car and talking to Janis, when Janis says 'he still doesn't want you' two extras in dark clothing walk up a pathway behind Cady. However when the shot cuts back to her, they have totally vanished. Even though they were wearing dark clothing, you'd still be able to have seen them, and there was not enough time between the different shots for them to have walked into the house.
Continuity mistake: When the principal is introducing Cady to the class, the amount of donuts on the desk changes between shots. In some shots there are two donuts on top of the donut box, and other shots there are no donuts.
Continuity mistake: When the Plastics are explaining to Cady the "rules" at lunch, an extra in a red shirt walks directly in front of the camera, and then a couple of seconds later, she walks in front of the camera again walking the same direction that she was walking the first time she passed the camera.
Continuity mistake: While the girls go wild in the hallway, the principal breaks the glass with a bat making the sprinklers come on. When he yells, "All junior girls report to the gymnasium immediately," in the following shots all their shirts are dry.
Continuity mistake: In the winter talent show scene, you see Gretchen go to kick the boom box in hopes of fixing the skipping CD, but when she kicks it you see it start to just fall off the stage. Yet in the next shot the CD player shoots forward and hits Gretchen's boyfriend, as if she had kicked it a lot harder than she actually did.
Continuity mistake: In the Spring Fling scene, when Cady and Aaron are dancing, it alternates shots between Cady's face and Aaron's. Her arm is on his shoulder in one shot and the next shot it is on his arm. This happens a couple of times in the same section of that scene. Really obvious.
Continuity mistake: When the girls are rioting a boy gets on his mobile phone asking his mother to come and get him because he is frightened. The same girl in the stripy top and denim skirt runs down the stairs behind him twice within a few seconds.
Continuity mistake: When Cady enters the dance after the Mathletes competition, her sleeve is down past her arms and we cannot see her hand. In the next shot, the sleeve is rolled up and her hand is visible.
Continuity mistake: Just before Regina gets run over by the bus, watch her hair. It changes from on her shoulder to behind her neck between shots.
Chosen answer: The first time she goes in with Damian and Janice is their homeroom and when she is with Aaron it is the actual class.
Movieman123