relax and talk to them as if you were just teaching/ talking to one person. Take samples of different types of scrolling if possible. Talk about from start to finish from applying pattern to final cut. When I did one I was asked where I got the patterns, blade sizes/differences, and most important what saw to use. Get the group involved, if they (at least a few) are interested in scrolling and ask questions time will seem to fly by. If you are going to have a saw there let some try to cut with it.