This is a review class for an upcoming unit test on linear functions.
There are a number of ways to organize study sessions. I still find that most ninth graders benefit from having a study guide generated for them (in terms of cognitive development, the task of making a study guide and picking out relevant notes, etc. is a worthy, but overwhelming task for them!).
So I have a study guide that is split into two sections (which fits nicely into 2 45 minute classes or 1 90 minute class - which I am currently teaching). I arrange students into groups and like to mix up the ability level when preparing for tests. The reason for heterogeneous grouping is I find that the students that can complete the problems with relative ease benefit from having to explain or teach specific problems to students who are struggling more with the skills and concepts covered in the unit.
I like to assign a group of problems, and then reconvene the class to review the questions. As students are working on the problems in groups, I typically assign one problem that each group has to focus on and will have to review to the class.
We continue the cycle of group work, class review as we complete the study guide.
I like to complete the odd problems in class and then assign the even problems for homework - as a note, the study guide follows the type of questions found on the unit test, and there are two of each type of problem found on the test (for example, item 1 on the test should correlate to items 1 and 2 on the study guide).