Your average students thinks their teacher lives in the closet at the back of the room, and is not a real person. I take this to a different place by seeing teaching as acting. Every day I play a character named Mr. Claydon, or Coach Claydon, or Mister Coach Claydon. Who's he? A slightly arrogant, hilarious ex-engineer with five Ferraris and this house:
How'd he get the house? Founded a rap label and sold it for $300 million, duh. He answers questions with "because I'm awesome." He'll probably make a joke about your girlfriend, or use the vertical line test as a metaphor for a prom date. When a seated student asks him to turn in a paper for them, he'll walk all the way over to their desk and point "it goes over there" walking back and forth to the spot for effect, never touching the item the student has. He won't hestitate to use a stick figure drawing of you getting eaten by a shark in a math problem. He will blast Britney Spears during free work time. He will waste you in tic-tac-toe. And on and on and on.
Why? Well, teachers are there to make impressions on kids right? Nothing makes a better impression than the genius with bad jokes. Students will perform when they know that sometimes they get to have fun along the way, or that math class is a guaranteed laugh. No need to brow beat them with speeches on responsibility and not taking things seriously. If you know what you're doing and entertain the room, you will see far fewer blank spaces on a test.
Why again? There are times Mr. Claydon gets upset. Early on, Mr. Claydon establishes that there's a time and a place for fun, but there is work to do. Mr. Claydon gets upset extremely rarely, but it happens. Does he yell, scream? Nope. But whatever assistance was being given will stop, Mr. Claydon will pack up his things and leave the room. What does he hear as he observes from next door? Dead silence. We made Mr. Claydon go away, how'd we mess that up? When he returns and sits at his desk ignoring the room? Dead silence.
Get kids to invest in your character and they will respect what happens when they offend him. Word spreads and all of a sudden Mr. Claydon's other classes are wondering how in the world he got mad at That Bad Class.
Am I anything like this in real life? Not really. Ironically, public speaking makes me nervous, I don't like being social in large groups, and my house is not that big. It's not even a house.
So start yelling at them from day one if you want to, or give them someone quirky they have the privledge of learning math from, and see which version gets better classroom management results when it counts.