'We never have teachers': the students forced to learn alone

Imagine a year 12 double maths class with no teacher, where instead of learning, students are sitting on their phones during class.  Or a school where almost a quarter of all teachers are away.  That's the reality of what some schools are dealing with as teachers complain of a severe shortage.  Today, Background Briefing's Mayeta Clarke, on her exclusive access inside a classroom and why we should worry about what’s to come. Featured: Mayeta Clark, reporter, ABC Background Briefing