Teaching, Learning, and Communicating about Fractions
Part 2Video TranscriptTeacher:  The card we said we were going to talk
about this morning was eight-tenths.  Did anybody
think of a way in which you can move your piece
across to the other side if our card was
eight-tenths?Student 1: Instead of using eight-tenths, you
could use two-fifths, and you ­ no four-fifths. 
And you could go to four-fifths or eight-tenths.Teacher:  So I could go to four-fifths or
eight-tenths?  So one or the other?Student 1: Yeah.Teacher:  How did you know four-fifths was a good
move?Student 1:  Because eight-tenths and four-fifths
are equivalent.Teacher:  Ok.Student 1:  So both of them would work.http://illuminations.nctm.org/reflections/3-5/Fractions/part2.html