The students normally sit and settle down once the teacher enters the classroom, since the teachers move classes instead of the students. As the teachers conduct their classes, they general manage the students by glancing around and looking directly at any student causing a distraction to signal for them to stop, and it works. In other instances, I have hear the teacher use a form of 'shh' to briefly indicate they want silence, and the class helps out by shushing the students. The cooperation is incredible and makes a difference, but I am not accustomed to such simple techniques.
The various classrooms and teachers that I have been in at Maristas have used the same techniques. The 1 ESO students, in which I consistently observe English and occasionally sit in on math, are more active when I enter the classroom but settle down once Miguel joins me, as they know the day's lesson is going to begin. Throughout the various lessons that I have observed, students respond to questions when called on and readily participate. The community that I have observed at Maristas is very close-knit and I thoroughly enjoy being a part of it and being given the opportunity this semester. It has broadened my perspective on how schools function and gave me the chance to experience general learning in another language and learn more about Spanish in addition to many aspects of teaching.