Marlene Sokol and Ian Hodgson

Each day, 18,000 students take their seats inside Hillsborough County’s most struggling schools, enough to fill a small city.

The county by far logged more schools with D or F grades than any other in Florida, according to state numbers released in December. In all, 33 elementary and middle schools.

The vast majority of students in those schools come from poor families, with stresses at home that can hamper their ability to learn.

They are kids who need the most from their school district. Yet they are more likely to be greeted in class by a substitute teacher, or one with far less experience than those at higher-performing schools, a Tampa Bay Times analysis found.