In grade 3, students are expected to be able to represent a fraction on a number line by first identifying the interval from 0 to 1 as the unit and by partitioning the unit as needed on the basis of the denominator. This task extends these grade 3 fraction goals stated in the Common Core State Standards for Mathematics (NGA Center and CCSSO 2010) and offers opportunities to expand on these ideas and reinforce knowledge required for grade 4 standards. uncover students' reasoning. The purposes of this article are to share tasks with teachers, produce samples of student work, and highlight ways to promote productive discussions. The use the Five Practices for orchestrating productive discussion (Smith and Stein 2011) and offer ways to anticipate student thinking based on their work with elementary school students, ideas for monitoring student partner work, and considerations for selecting, sequencing, and connecting student thinking. A short description of the Five Practices is also presented.