The co-construction of arguments by middle-school students

This paper highlights the value of student collaboration in doing mathematics, demonstrates how urban, middle-school students, working together, co-constructed justifications for their solutions, and shows that certain conditions are associated with the promotion of a culture of reasoning. It is documented that students collaboratively built arguments that took the form of proof, challenged each others’ arguments, and justified these arguments in small groups and whole class discussions. In producing their mathematical justifications, students included the input of others. Finally, the way in which students, by expanding on the arguments of others, also used alternative forms of reasoning which in many cases led to even more refined arguments is discussed.