I wrote the levels of this assessment to be used flexibly. In general, I consider the Level B problems to be “proficient,” and the Level A problems are modified. The Level C problems clearly go beyond the standards. Feel free to group the problems differently—one strategy is to give each student one page of problems that are all at the same level and give them the chance to make sure this is the right level for them. Another strategy is to group the problems by skill or topic and ask students to choose one problem within each group to solve. Either way, students need to be included in the decision making process—the whole purpose of providing work at different levels is for students to engage in the self-assessment process and to show them that they are capable of choosing a challenge. So often in school we as teachers require students to do things, or force them to, that they forget that they actually enjoy challenges—they like to learn, they want to tackle the most difficult problems that they are able to, and they want to fully understand what they are doing. Including them in the choice of which level of problem to work on, and not assigning external rewards or punishments to different levels, gives them the opportunity to find their intrinsic motivation.