Learning about Area, Perimeter, and Fractions with and from PeersPart One Video TranscriptTeacher: What I would like for you to do is look
 at all the shapes that you've made at your
table and discuss this question with, with the
people sitting at your group: what can happen
to the perimeter of your shape when you add
one tile? (Several students are speaking at
once.)Girl 1: ... and then you add another one, and 
then it's 18, and then if you add another one 
it's 20.Girl 2: Well, it depends where you put it. 
Like if you just put it here it'd be the same
one.Girl 1: (simultaneously) . . . just be the
same...Girl 2: But if you put it on only one side of 
another box it only adds, it adds two instead 
of (inaudible).Unseen Child: Can it go smaller?Girl 3: What are you gonna say?Boy 1: When you're (inaudible) it will stays the
same. Um, if you go around here it will
subtract, um, a side. Uh, it will subtract one
from the perimeter and...Girl 4: So two of 'em taking away? And then, 
you're going to be adding three or two? 
'Cause like if you're putting it there...Boy 2: I know this...Girl 4: two ...Boy 2: I know it, it, it takes away two and it 
puts back two. So it's the same here. See, 
but what about here, though?Girl 4: That's take away two ...Boy 2: 14. Wait, alright.Girl 4: (simultaneously) ... and keeping three.Boy 2: ... 14, 15, 16, 17.http://illuminations.nctm.org/reflections/6-8/LearningWithPeers/part1.html