I always do my lessons step by step but I try to make each demo on a different
day. If you are stopping them after you have them working then it becomes
difficult for the student that might not be finished with the previous demo
and will not want to stop to see another. Instead make a demo and explanation
for what you want them to do each day. Then do a different thing with them on
a different class day.
My students know now that they should try to complete what I tell them to do
before they go on and then we can do very complicated things and they don't