Visible crew/equipment: At the start of the first scene in the diner, just as we hear Sam begin to say, "At Hal's, everyone felt like family," the actor's green T-mark is visible on the floor, where Eleanor was just standing. (Visible on fullscreen DVD.) (00:01:45)
Continuity mistake: At the beginning of the movie when the younger version of Sam is blowing out her candles, the amount of ice cream in the cup next to her changes within seconds. (00:02:10)
Continuity mistake: After young Sam loses her father in the Northridge earthquake (noted in voiceover), she appears alone on the ball field, at home plate. In the close-up much of the area is in shadow around her, but in the next wideshot the entire area is in sunlight with only the fence/backstop casting thin shadows. (00:04:30)
Continuity mistake: After young Sam has carried the box of her belongings up to her new bedroom in the attic, she lies down on her bed and as the camera pulls back the window shade is all the way up. It cuts to a wideshot as the camera still pulls back in the rain, and the shade is lower now. (00:05:20)
Visible crew/equipment: At the pool, when Sam brings the salmon plate to Fiona, just as she rushes down the stairs, the shadow of the boom mic and pole is seen moving from right to left, along the grass. (00:06:40)
Audio problem: When the twins are practising in the house pool, Brianna farts and you can hear her say "whoopsie", but her mouth doesn't move. (00:07:10)
Continuity mistake: When Sam is at Carter's house to give him a lift to school, Carter (in his Snoop Dizzle look) is holding the script in his left hand and the bag's strap falls off his right shoulder when he sits down. Next shot, the script is in his right hand and the strap is back up on his shoulder. (00:11:00)
Visible crew/equipment: When Sam is giving Carter a lift to school, after Carter closes the passenger door, just as the camera moves in closer the reflections of moving equipment (likely the boom) and a crew member are visible in the vent window. (00:11:05)
Continuity mistake: After Sam loses the two parking spaces to Shelby and then Austin, when it cuts to Shelby, Caitlin and Madison walking down the corridor pushing everyone aside, Madison is holding her textbooks with the books' spines facing forward, then facing the opposite way, and finally back again. (00:13:35)
Continuity mistake: At the start, when Sam is reading the text message from Austin stating "Where have u been? We haven't talked...", on the cell display there are two bars in the battery icon in this close-up, but as she replies "We talked this morning", the battery icon is empty in the semi close-up. Then, when she reads his reply in the close-up, once again there are two bars in the icon. (00:14:45)
Continuity mistake: When Sam is sitting on the friendship circle you can see that her legs are crossed the entire time. When she texts Austin you see her legs and they are not crossed. In the shots before and after this one her legs are crossed. (00:14:50)
Continuity mistake: At the dance Sam is wearing silver non-platform stilettos with silvery nail polish on her toenails. As soon as Fiona and the "Siamese" twins leave the diner, in the kitchen a much relieved Sam shifts her white gown and she is wearing white platforms and her toenail polish is quite gone now. (00:32:35 - 00:50:45)
Other mistake: When Conner is setting the time for Sam to be back at the diner by midnight, the phone isn't on. (00:32:47)
Continuity mistake: When Fiona picks up the twins at the dance, the rearview mirror on Fiona's Jag disappears on the way back to the diner, but reappears when she pulls into the diner parking lot, then it disappears again. (00:46:45)
Continuity mistake: After the dance, when Fiona and the twins are in the Jaguar, and Carter and Sam are in the Mercedes, all driving to the diner, the views of the side streets they pass change back and forth, between close-ups and wideshots. (00:47:25)
Revealing mistake: After the dance, during the Mercedes vs. Jaguar "race" back to the diner, much of the entire scene takes place at the same intersection of Victory Blvd and Olive Ave, filmed from different angles. Note the Jiffy Lube and Enterprise (cars) on the corners, which are actually across the street from one another. (00:47:25)
Continuity mistake: When Fiona and the "Siamese" twins are at the diner, Sam pops up from behind the window counter with some flour on her baseball cap, but in Sam's next close-up in the kitchen there is instantly much more flour on the cap. (00:50:40)
Visible crew/equipment: In the diner's parking lot after the dance, when Carter slams the Mercedes into the sign pole, in the close-up of the car's front end the reflection of a crewmember is visible on the chrome grille. (00:51:25)
Visible crew/equipment: When Austin is putting up the Cinderella fliers at school, in the first shot as he, David and Ryan walk forward, the blue actor's mark is visible on the floor behind Ryan, where he and David were just standing. (Visible on fullscreen DVD.) (00:52:50)
Continuity mistake: When Austin is putting up the "Have you seen Cinderella?" fliers, in one shot he puts up the second flier on the blue door on the lower left side of another flier, but in the following shots, the flier is near the center, then to the right, and then back near the center again. (00:53:05)
Answer: Yes, this happens in most schools. The reason is that students are more likely to pay attention to announcements that are not made by a boring school employee. In many American schools, we have a phenomenon known as "home room". This is a short period usually first thing in the morning that is non-instructional when announcements are made, forms are filled out, and administrivial functions that don't have anything to do with any one class. At schools that don't have this, they have a thing called "study hall" or "independent study" which is a period where you sit in a classroom and work on your assignments, special functions for the school admin. like you are talking about are frequently done at these periods by students who are "working in the office" rather than studying. Then, there are schools that actually have classes in journalism, broadcasting, etc. where this activity would be part of the schoolwork.
Myridon