Students can be organized groups of four students when engaging in the Rethink section.
The following roles can be utilized if there are two independent gear ratios:

Role 1 : This person will calculate the first row of the Calculation Table (Gear Ratio 1).

Role 2 : This person will calculate the second row of the Calculation Table (Gear Ratio 2).

Role 3 : This person will calculate the third row of the Calculation Table (Resulting Ratio).

Role 4 : This person will determine the fourth and last row of the Calculation Table (Advantage).
The following roles can be utilized if there are three independent gear ratios:

Role 1 : This person will calculate the first row of the Calculation Table (Gear Ratio 1).

Role 2 : This person will calculate the second row of the Calculation Table (Gear Ratio 2).

Role 3 : This person will calculate the third row of the Calculation Table (Gear Ratio 3).

Role 4 : This person will calculate the fourth row of the Calculation Table (Resulting Ratio).

All Roles : The group together will collectively determine the fifth and last row of the Calculation Table (Advantage).
If there are two students in each group, the students can each choose two roles. If there are three students in a group, one of the students can choose to do two roles. If there are four students in a group, each student can have one role.
Provide the list of roles and their definitions to the students. Once students are in their groups, allow the members to choose their role. Circulate the classroom and makes sure that every student has a role. There is an optional collaboration rubric on this page (Google Doc / .docx / .pdf).
Remind the students of roles throughout the exploration. For roles to work, students have to feel as though they will be held accountable for fulfilling those roles. Therefore, interject if you see a student taking over someone else’s role or not fulfilling their assigned role. Reminders about who is supposed to be doing what can be useful interventions.