Focus

The focus in the CCSS-M is a response to “mile wide, inch deep” nature of US math curriculum.  The emphasis is on developing deep conceptual understanding, which lays the foundation for future learning

Focus strongly where the Standards focus

The Standards call for a greater focus in mathematics. Rather than racing to cover topics in a mile-wide, inch-deep curriculum, the Standards require us to significantly narrow and deepen the way time and energy is spent in the math classroom. We focus deeply on the major work of each grade so that students can gain strong foundations: solid conceptual understanding, a high degree of procedural skill and fluency, and the ability to apply the math they know to solve problems inside and outside the math classroom.  

- from achievethecore.com see more