Heads are scouring the world for teachers. One in four maths vacancies remains unfilled, according to this month’s TESSecondary Heads Association survey. Technology is in the same plight, while the figure for science is one in six.

Such statistics make bitter reading for Richard Dallow, Mike Robinson and Teresa Hunt - teachers respectively of science, technology and maths. Richard’s most regular employment is as a poorly paid care assistant in an old people’s home; Teresa is temping as a secretary; and Mike is helping adults at an open-access centre.

Richard and Teresa are mature teachers with years of experience. Mike, a former dockyard worker in Plymouth, did an engineering degree in his late thirties followed by a PGCE course at 43. All three fear that age and experience have priced them out of the job market. Schools would rather employ a young NQT.

Richard, a science teacher for 14 years, was made redundant in 1998 when his Birmingham secondary school dropped general national vocational qualifications. Now aged 44, he has been unable to find another permanent job. His income for 1999 was pound;14,000.

“I am told I am in the ‘too oldtoo expensive’ category. All I can get are short-term positions, which involve an inspection. I do all the paperwork, revise the schemes of work, put in a good performance in front of the inspector, and am then dumped in favour of a cheaper alternative.”

Family commitments can prevent older teachers moving to find work, but Richard is prepared to travel. He lives in Birmingham, but has worked on supply in London. To make ends meet he has to take on other jobs. “Quite often I do a day’s teaching and then a 5-11 evening shift as a care assistant in an old people’s home.

“When I read about the shortage of teachers, especially in science and maths, I wish a truer impression could be given. It is not so much a shortage of teachers as a shortfall of money to pay them. This has the effect of creating a demand for perhaps younger, less expensive teachers, while leaving people like me almost unemployable.”

Mature applicants can never be sure whether they are the victims of tight budgets, ageism, or both. The National Association of Schoolmasters Union of Women Teachers believes ageism is a problem, and has put it on the agenda for its next meeting with the Teacher Training Agency. Olwyn Gunn, the union’s education and equal opportunities secretary, says older staff are stereotyped as inflexible, uncreative, and unable to adapt to new technology. “The attitude that new is good should be challenged. Schools need a balance of staff, and ageism threatens that. It is particularly a problem for women who have left to have children at an older age and find they cannot get back in.”

Teresa Hunt agrees. The former deputy head of maths at a London secondary left her job after eight years to have a baby. She thought it would be easy to return, but ended up working on supply for three years. Eventually jobs came up at two schools where she had had short-term contracts, but she was not chosen.

Both schools “dispensed” with Teresa’s services when they found cheaper and younger staff. One did not even interview her. “The head candidly admitted that the budget would not stretch to paying my salary. I reminded him that my salary was not significantly greater than the cost of hiring me through an agency, so it would have been cheaper fr him to employ me under a temporary contract. However, he simply said that this was ‘not an economical option’.”

Like Richard, Teresa believes the real shortage is of money rather than teachers. Unlike him, though, she has had enough. “WhenI found myself working as a classroom assistant, I decided that my teacher career had reached both its nadir and its end. Since January I have been doing temp work for a secretarial agency. I loved teaching. I am sometimes tempted to try again, but the bitter memories soon deter me.”

Last year the Government launched MS600, a programme to recruit and train mature people as maths and science teachers. It was run by Geoff Brown, head of the Yorkshire and Humberside branch of the teacher supply agency, TimePlan. A former headteacher, Mr Brown says the cost of experienced teachers has always been a problem, particularly for small secondary schools on tight budgets. “If two or three young teachers leave and all the applicants are older, you know you are going to be left with a massive hole in your budget. It is a continual pressure for a head.”

As a governor of two primary schools, Mike Robinson knows about this pressure. In his five-year search for a job he has offered to negotiate on the extra cash his engineering experience should bring him. “After all, schools are paying a lot for inexperience,” he says. “Some may value my background, but others won’t appreciate it.”

He partly blames himself for his lack of success, saying that he and his wife were reluctant to move out of the West Country. But he is not bitter. “I’ve grown with the experience. I’ve been able to move into adult education, to take evening classes and to help unemployed people. After all, you go into teaching for the good feelings, not the money.”

In an ideal world, says Geoff Brown, heads need to keep a balance of ages in a department. So in theory they should snap up an older applicant to season a young staff. “But a successful department of relatively young people might fear that an older person with loads of experience would want it all done their way. Heads wouldn’t want to upset a maths or science department these days. You cannot afford to have them all leave.”

Persuading older teachers that all is not lost is routine for Dilly McDermott. Head of employment-based routes into teaching at Goldsmiths College, London, she also runs the return to teaching course. This is aimed at staff in the PIT - the “pool of inactive teachers”. In 1998 the PIT contained an estimated 300,000 teachers - many of them over 40. Dilly McDermott says the first thing many applicants do is apologise for their age. “If the media say you are about to pop your clogs at 60, you start to believe it. I have to stop them doing that. I have to change the mindset. I ask them, ‘Exactly what are you too old for?’ ” She criticises the TTA ads for focusing on young people and believes ageism is a serious problem for teachers, particularly in the search for promotion. Her students are warned: “It is going to be difficult getting a job if you have taken a break, and doubly difficult if you are mature. Schools should be open, inclusive organisations with good equal opportunities policies. But the ones that look at a person’s qualities rather than age are rare.”

Still, by emphasising the positive, by getting her students to talk up the value of age and experience, Dilly McDermott has found jobs for the majority of her returners. The oldest so far is 62. He is now happily teaching maths in London.

Richard Dallow and Teresa Hunt are pseudonyms