One of my best classes this year had a bad week last week. Only a fraction of the students did their work on Friday and the fraction of students working had been decreasing all week. I am not sure what is going on with them. The only thing I can think of is the week prior to this, we had a difficult unit that quite a few didn't understand. I tried teaching it multiple ways and even used some online games on the iPads. This helped some but not all. What can I do to get them back on track before a lack of work becomes a habit. I have never had so few students working.