The CRA can be done as rotating stations or whole group with one problem at a time. 

CRA stands for "Concrete, Representation, and Abstract (algorithm)". The purpose of a CRA assessment is to learn about how your students understand a certain concept. This CRA assessment will help you determine if your students have conceptual understanding of percentages and proportions within context, or if students have only memorized the algorithm of setting up a proportion and cross multiplying. By eighth grade, students should be able to apply the algorithm to conceptual understanding.