I have 2 x year 7 classes mixed ability, disadvantaged area, high English as a 2nd Language and a huge range of academic levels. I am having problems getting there attention when I want to start direct teaching at the front and keeping the working noise level down to a dull roar. I find I am constantly calling out names one after the other for many minutes, raising my voice over the noise and worst of all always threatening kids with staying behind after class for "'minutes owed to me". (this last measure seems to be the only thing that works) It feels like a very negative environment. What are some tips for getting their attention without punitive threats? How do I get them to work with a low level of noise?