Trinity Academy is also having to draft in other subject teachers to cover maths lessons despite advertising the posts twice.
Headteacher Bryan Paterson cited the “national shortage” of teachers in subjects such as mathematics, science, technology, business and home economics as the cause of school’s crisis.
One parent said he was “astonished” when he read the letter and said he was worried about the consequences. Edinburgh council’s education convener councillor Ian Perry said he was working closely with the school to minimise disruption to learning.
In the letter to parents, Mr Paterson explained that the school had been trying to recruit two maths teachers but was unable to find suitable candidates.
“I write to assure you that plans have been put into place to mitigate against the national shortage and to ensure that all classes are supported by mathematics teachers.
“Where necessary, maths teachers may also share some classes, particularly in S1-S3, with colleagues from other faculties who have a mathematics background.
“Finally, if any parent can support us in any way, or knows anyone who might be able to do so, please contact me directly.”
Pupils hardest hit by the new ad hoc teaching arrangements will be those in S1-S3 at the school which has just over 800 pupils.
The letter does not make clear what form the support from parents could take.
In March, parents at Blairgowrie High school, in education secretary John Swinney’s Perthshire North constituency, received a letter from its headteacher appealing for “any parent with a maths or related degree” to come forward and help out as the school was struggling to fill maths teacher vacancies in the run up to exams.
The letter led to angry exchanges between First Minister Nicola Sturgeon and Tory leader Ruth Davidson at First Minister’s Questions,
One parent with a child in S1 at Trinity Academy said he was concerned about the possible long-term consequences to youngsters.
“I was astonished when I read the letter. I know there are problems getting people into teaching but for a subject as fundamental as maths to go uncovered is a disgrace.
“Especially since it looks like it’s the children in the lower years who are going to be most affected.
“What sort of start to secondary education is this? I’m worried we’ll be dealing with the impact of this for years.
“The idea of staff from another subject teaching maths doesn’t fill me with confidence.
“And the suggestion that parents might step in is laughable. Maths teachers are supposed to have a degree in their subject as well as going through teacher training.
“I’m really worried about the consequences. But I can’t blame the school. This is a wider problem that needs addressing by the council and the Scottish government.”
Last night education convener Cllr Perry said the council was liaising with Trinity Academy to safeguard the quality of pupils’ education.
“In common with many Scottish local authorities vacancies in maths are more difficult to fill.
“We want to reassure parents that we are working very closely with the school to support them over this temporary shortage and to minimise any disruption to the pupils’ learning.
“Our priority remains ensuring that the curriculum continues to be delivered to the highest possible standard.”
Iain Gray, Scottish Labour’s Scottish Labour’s education spokesman, said the Trinity Academy letter was a “second humiliation” for the Scottish Government and that only a wide-ranging overhaul would resolve Scotland’s teacher recruitment and retention problem.
“This is utterly humiliating for the SNP government.
“This is the second time a head teacher has been reduced to writing to parents asking for help with teaching maths. Last time, it was in John Swinney’s own constituency, this time it is in Scotland’s capital city.
“It lays bare the state of education in Scotland after a decade of SNP government. Under the SNP we have a workforce crisis in our schools, with 4,000 fewer teachers and £1.5 billion cut from local authority budgets since 2011.”
Liz Smith, Conservative shadow education secretary, said unfilled vacancies in Scotland’s capital, rather than in rural areas which can find difficulties in attracting applicants, was a “scandal”. She added: “This is a remarkable development which exposes the scale of the SNP’s teacher recruitment crisis.”
A spokesman for the Educational Institute for Scotland teaching union, said: “Teacher recruitment does remain a challenge across the country and, in particular, in certain subject areas including STEM (science, technology, engineering and mathematics) subjects such as mathematics.”