Use the freeze on the doc cam.

Often on a worksheet I will work through an entire problem on the doc cam, very slowly and carefully, step by step with the students.  Typically I will then ask them to work together on the next problem.  I try to work my way around the class to give help and implement some teacher check points to see if they are picking up my objectives.  I move back to the doc cam to set up the finished problem, but now I either rush through it (prone to simple mistakes) or I continue slowly which is what I did on the first problem but I probably, but not necessarily, don’t need to do now.  My cooperating teacher pointed out how awkward my doc cam teaching was and the simple solution was the freeze button.  As the students work the problems I can freeze the unanswered problem on the doc cam and work it out carefully until it is ready to project, and not give away the answer.  I started to incorporate this into my lessons but I prepared the worked out problems before class so I did not loose any time circulating, helping, and assessing.  It seems obvious in retrospect but I have so much on my mind during lessons I often mangle these small details.