Unintentionally, I stumbled on a phrase this year that worked very well with my high school students (I also had large classes of Freshman). I would simply say, "Focus Forward" and then put my eyes on the clock. If students were not all looking forward and quiet within 30 seconds, I would begin to write the time on the board in 10 second increments. Just the idea that I was writing time on the board would grab everyone's attention! Only one time did I get past 60 seconds. Students would ask me what the time meant but I never told….just would say, "You really, really, REALLY don't want to know!"
Some teachers do use the 'watching the clock' method and hold the students extra time (this depends on your school's policies), or give more homework (doesn't work for students who will not complete HW anyway), or give a quiz if they reach a certain amount of seconds.
For me, I don't want schoolwork or homework associated with punishment. I did have a contest during a very challenging week (right before Spring Break) in that I kept running totals by class periods on my whiteboard. The class with the least amount of 'seconds' earned a reward day. That worked very well - so well, that I will use it again this year!
I use PAT (in other words known as earned free time). They earn 4 minutes / day, I have 4 lines on the board symbolizing the minutes. When things don't go well, I start erasing half a line or a line (30 seconds or 1 minutes). It's surprising how much they care and they tell each other to shut up. The worst thing I end up doing is actually erasing a minute. No yelling, no threatening.
I have done something similar but instead of using lines, I used marbles in a jar. Each class period is a different color marble but all marbles are in the same clear jar (fishbowl). I pull out a marble when the class doesn't follow a procedure and usually say, "You're losing your marbles!" The students see immediately the loss and where they stand with the other classes. The class with the most marbles at the end of the week earns a 15 minute reward (one high school class begged to play Heads Up-7Up!) But, I have to be careful that the bowl of marbles is far from students and put away if I'm absent. Yes, students love to steal marbles
I prefer to take the silent approach. If I stand at the board, I expect my students to pay attention. If I'm teaching and they start talking, I will keep writing or flipping through the PowerPoint but I won't say a word.
When I had a really large class with a lot of loud mouths, I looked up suggestions on Pinterest. I presented all the options to them and let them pick. I forget what I said but the entire class responded "Mac and cheese." Honestly, the students may love your elementary school tactics.
I think all of these attention getting statements mentioned can work fine (except the guy that says "shut the f up"!! ). What's really important is that you learn names as quickly as possible. Once you say, "ok, guys, listen up!" you'll probably get 95% compliance. Saying, "Johnny, Susie, I need you to listen up," will quell the rest of the conversations, then start the lesson.
"Confusion is always the most honest response." - Marty Indik
Big difference whether this is for the sub or a regular classroom teacher. Subs will continue to struggle while there is an easy give and take with the regular teacher. I have been both, so I have experience. As a sub, I would get the seating chart out, look at a talker, and start writing names on a piece of paper, without any emotion or explanation. Someone will always notice and soon there is a quiet as everyone begins to believe that there will be trouble for those on the list. When quiet, I would simply fold the sheet of paper and put it in my pocket, no explanation. I still do something similar as a full time teacher, choosing absolute silence over almost any other method. Writing a pun of the day on the board as class begins is a quick way to get all eyes on you. Once the eyes are on you, get going with the lesson.
I'm rather short, so I hold my hand up and say 'hi five" then count down from five. The expectation is that they are silent LONG before I get to five. By three they are smacking each other on the arm telling each other to quiet down.
I also explain to my class, whether I was in my own class or subbing, that I find yelling at my class rude and won't do it. Therefore if there are people who are making it necessary for me to raise my voice are the one risking further disciplinary action.
I've never had to send anyone out after that when subbing.