According to a 2012 study from the Program for International Student Assessment, twenty-nine out of sixty-five participating nations and other jurisdictions outperformed the United States in mathematics by a statistically significant margin (up from twenty-three in 2009) (Heitin 2013). To improve students' mathematical understanding, the authors argue that educators need to focus on fewer topics in greater detail. To accomplish this, the Common Core State Standards (CCSSI 2010) highlights specific mathematical skills and concepts with a three-step approach: focus, coherence, and rigor. The inclusion of modeling, as a Standard for Mathematical Practice and also as a content category, demands a more rigorous understanding of mathematical tools and how they can be used in everyday situations. This refocusing requires an overhaul with new books and other materials geared toward this new approach. To ease the transition for in-service teachers, this article provides suggestions on how to incorporate modeling into the classroom with the resources already available. A bibliography is included.