Over 5,000 complete Common Core-aligned lessons from 130 Master Teachers.
This site provides classroom videos and lesson samples designed to illustrate the Mathematical Practices in action.
Sample website of a district curriculum
Mathematical thought-provoking pictures and videos
Mathematical tasks in context following a three-act format
Curriculum modules include sample assessment tasks
Free materials as well as items to purchase at a nominal fee; well-aligned to the common core!
The main goal for this project is to provide guidance to states, assessment consortia, testing companies, and curriculum developers by illustrating the range and types of mathematical work that students will experience in implementing the Common Core State Standards for mathematics.
Dear Educator Leader, We have prepared the following letter to assist you in garnering support from your principal or district leader to attend the AML Annual Conference.  Feel free to customize the document to help "make the case" for your attendance.  
MAP assessment projects
Curriculum modules include performance tasks
NSDL contains digital learning objects that are related to specific Math Common Core State Standards.
National Council Supervisors of Mathematics collections of tasks for illustrating the practices
Illuminations provide standard-based resources that improve the teaching and learning of mathematics for all students. These materials illuminate the vision for school mathematics set forth in Principles and Standards for School Mathematics, Curriculum Focal Points for Prekindergarten through Grade 8 Mathematics, and Focus in High School Mathematics: Reasoning and Sense Making.
Challenging math problems worth solving
Sample web-based practice items
Sample items and performance tasks
Access free, ready-to-use, standards-aligned classroom activities for middle grades through high school. Activities include student worksheets and teacher notes to support the CCSS and Standards for Mathematical Practice.