I have closed this lesson a variety of ways in the past. Sometimes, I simply ask students to do a gallery walk of all the posters after they are glued and hung on the walls. Students literally walk about the room in a set pattern and leave post-it note comments on each other's posters. Sometimes, I have one group present a particularly difficult match under the document camera. Other times, I have closed without a public presentation of student work but instead took pictures with my ipad and post them to Edmodo.com with questions for students to answer as homework that night.