Common Core Essential Elements Mathematics

particular mathematical statement is true or where a mathematical 
rule comes from... Mathematical understanding and procedural skill 
are equally important, and both are assessable using mathematical 
tasks of sufficient richness (CCSSM p. 4).
While the Standards for Mathematical Practice should be addressed with 
all of the  
Standards for Mathematical Content
, the content standards that begin 
with the verb 
“understand” are a natural intersection between the two.
K-12 Coherence and Convergence
The Standards for Mathematical Content are built upon 
coherence, 
one of the design principles of the CCSSM. The intentional progression 
and sequencing of topics lays the foundation for the mathematics that 
is developed from kindergarten through high school. The diagram 
below depicts how domains at the elementary and middle school 
levels converge toward algebra at the high school. It is important 
that educators are knowledgeable about these progressions so that 
students learn mathematics with understanding and so that new 
content can build on prior learning