For over 10 years, research of maths education in first world countries has reached the conclusion that maths education in the US needs to become a lot more focused to improve the level of mathematics achievement across the States. In order to achieve this, the common core standards for maths are designed to tackle the issue of a curriculum that can be classed as far too broad.
The new common core standards build on the best of the math standards from all States across the US. They also take elements from the best mathematical practices across the globe, as well as input from other areas such as state departments of education, educators, professional bodies and of course children and their parents.
The common core math standards aim to provide clarity, drill down into the general core statements. In following the format foregone by William Schmidt and Richard Houang, by often returning to the core math principles such as the laws of arithmetic.
Also, the order of sections and topics that are outlined in a body of math standards must adhere to what is already known about how children learn the best. The development of the core standards began with learning progressions being researched, detailing what is known today about how childrens maths knowledge, skills, and understanding can and should develop over a period of time.
The aptitude children need to be prepared for maths in schools and beyond are interlinked throughout the maths core standards.
Be sure to see this example of a Lesson Plan Template, incorporating the ICAN statements for Math.