VIERA, Fla. – Four days before the first day of class for Brevard Public Schools, the district said there are still thousands of unregistered students.Most of them are in the elementary schools where the district said they have 6,000 fewer students registered for this year compared to last year."We need people to contact their school if they are planning on coming back and have still not contacted the school because we have a few thousand students that haven't reached out and registered yet," school board member Tina Descovich said.That means teachers do not know how many of their students will actually show up Monday.The teachers union said a lot of parents are making last-minute decisions for their families. "What we're telling teachers.