On a visit to a school in Sydney's southwest, new NSW Premier Chris Minns popped his phone into a plastic container - a ritual tens of thousands of students will go through daily from October.
The promise to enforce a ban on mobile phones in every public high school classroom would come into effect from term four, Mr Minns said on Monday.
The ban - a Minns government election pledge - would bring high schools into line with public primary schools as well as schools in Victoria, South Australia, Western Australia and the Northern Territory.
"I don't want to see NSW kids fall further behind in educational attainment as a result of having a constantly pinging mobile phone device sitting on their lap or tweeting in their ear while they should be undertaking learning in the classroom," Mr Minns said.
"I know that many adults find it almost impossible to concentrate with a mobile phone device in their hands.
"(Without a ban) we're expecting children to be able to concentrate on the lesson in front of them and have the discipline to focus in the classroom."
The education department will consult with schools from Monday on how to enforce the ban, which will impact about 320,000 students in 400 schools.
Education Minister Prue Car said the change was long overdue and would help teachers perform their jobs without being distracted by students using phones.
"It makes sure that at recess and lunch, kids can actually socialise together, engage in physical activity, run around and actually not be sitting in playgrounds, on the floor, on their phones on social media or playing games," she said.
Each school will be able to decide how to implement the ban.
Condell Park High School has students deposit phones on trolleys at the start of each school day and pick them up after the final bell rings.
Principal Susie Mobayed said the rule had been in place for 16 years and prevented cyberbullying and constant distractions from notifications and messages.
"The kids arrive in the morning, they put their phones in plastic bags with their names on them," she said.
Other schools use lockable pouches, lockers, bags or make students hand in their phones at the beginning of the school day.
Ms Mobayed knows the ban isn't perfect and some students won't comply.
"We're not silly - we know that some kids might have a phone in their possession," she said.
"But it's about them not accessing it."
