The Inside Mathematics website hosts tasks that are “grade-level formative performance assessment tasks with accompanying scoring rubrics and discussion of student work samples.” The tasks are aligned to the Common Core State Standards for Mathematics, ranging from Grade 2 through high school (algebra, functions, geometry, and statistics and probability). The tasks are available “for professional development purpose”s without modification.
http://www.insidemathematics.org/performance-assessment-tasks
These tasks were developed by the Mathematics Assessment Resource Service of the Shell Centre for Mathematical Education, University of Nottingham, England, and the Silicon Valley Mathematics Initiative’s Mathematics Assessment Collaborative.