Start with a small talk which introduces the target lesson for the day. When I did this lesson, it was just in time for Black Friday sale in Japan, so I raised the question, "If you could get 50% OFF, which item would you like to buy?"
After pair sharing and class sharing (by volunteers), introduce the situations. I decided to have 6 situations for the sake of groupings later, where each group has 6 members.
After reading with the students all the situations, ask them to make groups and hand them in the worksheet. By this time, students don't know that the worksheets are different. What they basically do is get one copy and pass the rest to the other members. Let them look at their worksheets then to find out they got different situations. Go back to the situations and check who got each situation in groups.
Give them 10 minutes to answer the worksheets. I and my JTE usually take this time (during writing time) to help students with their vocabulary needs and also ask questions from their answers.
When 10 minutes is up, or when everyone is finished, let members share their answer to the group. This usually takes 2~3 minutes only since they read from the worksheets. You may encourage them to ask questions to the members.
After every group is done with sharing, start with random select (pptx attached). I used colors and Ilet students to choose a color. Click on the color and it will reveal the situation. Ask each member of all groups to stand up (or stand up when it's their turn to share) and share their answers to the class.