“…This may include characteristics of tasks for learning (Hiebert et al, 1997;Stein, Smith, Henningsen, & Silver, 2000), the relationship between tasks and mathematical discourse (Boaler, 2008;Smith & Stein, 2011), and the role of task implementation and learning (Ainley, Pratt, & Hansen, 2006;Berry, Bol, & McKinney, 2009;Doerr, 2006;Henningsen & Stein, 1997). Van de Walle et al (2013) described features of problems for learning where learners must perceive such problems as "problematic" (p. 35).…”