Media playback is unsupported on your device Media caption Students at Forfar Academy share their opinions on the results of the much criticised Higher Maths exam

The pass mark in the new Higher Maths exam was significantly lowered amid concerns it was too difficult, it has emerged.

Candidates needed 34% to get a C and 60% for an A, according to the Scottish Qualifications Authority (SQA).

The exams body admitted the exam was harder than anticipated and said grade boundaries were adjusted accordingly.

Last year, a mark of 45% was needed for a C grade in Higher Maths.

Details of the pass marks were released as thousands of students received their results. Across all subjects there were a record 156,000 Higher passes - up 5.5% on last year.

Many had sat the new style exam which is being phased in this year and next.

The changes were designed to help fit them in with broader changes to education in recent years and were not, in themselves, particularly controversial.

However, the new Higher Maths did provoke a storm after the exam in May.

Image copyright SQA

Many students took to social media, claiming the paper was much more difficult than they had anticipated.

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Politicians united in congratulating students on their hard work, but Scottish Labour raised concerns about the low pass threshold in Maths.

Acting leader and shadow education secretary Iain Gray said: "It's true that pass marks are adjusted each year, but it's extraordinary to see this drop to just 33.8%.

"The Highers are the gold standard of Scottish education and this is a big concern."

Image caption Students at Forfar Academy were among those receiving their results on Tuesday morning

Scottish Conservatives young people spokeswoman Liz Smith said: "People would understand if modest modifications had been made to pass rates to reflect realistic changes in exams.

"But this reduction is drastic, and shows just how badly the SQA got it wrong."

Scottish Liberal Democrat education spokesman Liam McArthur said: "Cutting the pass mark for Higher Maths may help those students who persevered but it will do nothing for pupils who left exams early on after being presented with an exam paper including topics not covered in the coursework.

"Ministers must undertake a full investigation into why this happened."

The SQA said the grade boundaries had been adjusted to take into account the unusual difficulty of the Maths exam.

It said this ensured that candidates still received the grades they deserved. If someone who received a C last year had sat this year's exam, they would still have been awarded a C grade.

Education Secretary Angela Constance told BBC Scotland pupils adjustments ensured students received the "results they deserve".

She said checks and balances meant no student was disadvantaged by this year's "unusually hard" Higher Maths.

Speaking on the Good Morning Scotland radio programme, she added: "Despite the concerns it is clear that the qualification system has worked and if changes are needed going forward I can assure you that they certainly will be made."

More than 140,000 candidates were due to receive their results on Tuesday for a wide range of qualifications including National 4s and 5s, Highers and Advanced Highers.

Higher English passes were up 17.7% to 27,902

Higher modern languages passes increased by 15.2% to 7,419.

Advanced Higher passes have increased by 4% to a record level of 18,899.

Ms Constance added: "This is another strong performance by Scotland's young people.

"They have worked hard, and I congratulate each and every one of them, as well as the families and carers, and teachers and lecturers who have provided support.

"Scotland has seen record numbers of Higher and Advanced Higher passes. Students are performing particularly well in English and in modern languages."

Image copyright Getty Images Image caption A total of 107,295 pupils sat the new Highers

This year was the second year of the National 4 and 5 qualifications which replaced Standard Grades. A National 5 is broadly equivalent to a Credit in a Standard Grade or a good pass in an old O Grade.

There was a large increase in National 5 course entries, particularly among those taken beyond fourth year - with 229,870 A-C grades awarded.

S4, 5 and 6 are now grouped together as a "senior phase" in schools. The emphasis is increasingly placed on what qualifications a student has achieved by the time they leave school - usually in S6 - rather than what they have achieved by a particular stage.

For instance, some academically able youngsters may bypass National 5s to spend longer studying for their Highers.

Dr Janet Brown, SQA chief executive and Scotland's chief examining officer, said: "There is a broadening recognition of the different ways candidates can demonstrate their skills and achieve success, whether it be National 5, the new or existing Higher, Advanced Higher, Skills for Work or National Progression Awards.

"Employers require candidates to display a wide range of qualities. Our assessments and qualifications have been designed to provide people with the skills required to succeed today and in the future whether that be further study, training or employment."

Skills Development Scotland has a free exam results helpline which can offer advice to candidates whose exam results were poorer - or better - than expected.

The helpline will be open from 08:00 until 20:00 on 4 and 5 August, and from 09:00 until 17:00 daily until 12 August. The number to call is 0808 100 8000.