Back in March we studied geometry in second grade. To encourage students to notice geometry in the world around them, I gave cameras to groups of students and told them to find right angles and take pictures. I posted a slide show of the photos on our class blog.
I decided to have students take pictures only of their right angle and hand. This way, the right angle would be large enough to see. I also did not want to worry about posting kids' faces online. Many of the students photographed the right angles. This meant I could pick the pictures that were in focus and reject others. When I showed the slide show, students recognized photos they thought they took and I didn't have to worry about making sure I had photos from each group.