Teachers need flexibility to be able to tailor activities and lessons to each student's needs and abilities. We wanted to provide teachers that by tagging every problem our entire content library with its aligned Common Core Standard and allowing teachers to create custom problem sets. Teachers can “Search by Standard'' and find problems they want to provide students with extra practice focused on specific skills, topics, or standards . Once teachers find the problems they want to assign, they can customize a problem set containing only the problems they want to assign students. Here’s a video walkthrough of how to search by standard and customize problem sets.