... Mathematics educators have identified specific teaching practices, referred to as high-leverage practices, that address the need for ambitious teaching by improving classroom instruction and focusing on students' deep understanding of mathematics (Ball & Forzani, 2009;Grossman, 2013;Lampert et al., 2013). Examples of such practices include posing cognitively demanding mathematical tasks (Henningsen & Stein, 1997;Stein, Remillard, & Smith, 2007); promoting classroom discourse to enhance students' mathematical learning (Franke, Kazemi, & Battey, 2007;Smith & Stein, 2011); eliciting and responding to students' ideas (Jacobs, Lamb, & Philipp, 2010;Sleep & Boerst, 2012); orienting students to instructional goals (Hiebert & Morris, 2009;Sleep, 2012); supporting students' conversations about mathematics concepts (Boaler, 2006;Hufferd-Ackles, Fuson, & Sherin, 2004;Kazemi & Stipek, 2001); using and making connections among representations (Ball & Bass, 2003;Fuson, Kalchman, & Bransford, 2005;Stylianou & Silver, 2004); engaging students in productive struggle (Henningsen & Stein, 1997;Hiebert & Grouws, 2007); and questioning strategies that promote students' thinking (Herbel-Eisenmann & Cirillo, 2009). ...