Discussed, developed, and written over the course of roughly two-and-a-half-years, the Common Core State Standards (CCSS) seek to prepare students to be college- and career-ready (K-12 Blueprint, 2014). Released for implementation in classrooms nation-wide in June 2010, the CCSS are claimed to be “a balance of concepts and skills, with content standards that require both conceptual understanding and procedural fluency” (K-12 Blueprint, 2014, p. 3), as well as address the issue of mathematical curricula being described as “a mile wide and an inch deep” (Common Core State Standards Initiative, 2014). In order to abide by the newly adopted curricula, teachers must find ways to help students think more conceptually. This curriculum project on trigonometric functions at the Algebra II level attempts to do just that through the utilization of the Rule of Four in order to support students working within their zone of proximal development
