Mr Matthewson, 53, has taught for 32 years. He is head of Whitchurch high school in Cardiff, which has 2,400 pupils, 150 teaching staff and a pound;6 million-a-year budget.
He works an average of 60 hours a week. "The workload is much greater now, especially in terms of accountablity. We have to account not only for the children's progress but also for the quality of staff."
His long days are generally filled with meetings, interviews and paperwork. More often than not, his work extends into the evenings with governors' or parents' meetings. On Sunday afternoons he is usually going through some paperwork connected with school.
And he still teaches Year 7 every Wednesday. "It's something I do because I want to. It helps me keep in touch with the children. I can't say I have contact with all children in the school. But if I teach Year 7, it means I know a small group of children as they go up through the school, which helps."
His most crucial role, he said, was finding the right staff. "I am always on the look out for the best staff I can get, it's essential to the school. I'm very fortunate that we don't have any vacancies but I know other schools face a real problem in finding any staff at all - let alone the right people - which all adds to the pressure."
Eric Spear, 60, has been a teacher for 42 years. He is head of Staplehurst primary school in Staplehurst, Kent, which has 450 pupils and a pound;750,000 budget. "I have never worked so hard in my life in hours or multiple responsibilities," said Mr Spear who estimates he puts in 60 hours a week not including the work he takes home.
"And I am less in touch with the children. I still teach but I don't have a full-time class, I fill in the gaps. I cover for staff who are sick or away for some other reason, such as a training course.
"I was teaching only last week. It reminds me how exhausting it is. But I spend most of my time managing the school and the budget. And it's getting harder."
This is in spite of the school roll falling from 600 to 450 pupils over the 20 years that he has been head. And his school, he says, is a "nice school in a nice area" with few of the problems of an inner-city school.
"More bodies would help, especially in administration, as would the return of some trust to the professionals - the teachers - who have to account for every minute of the day."