The number of errors on this year's Leaving and Junior Cert exams was "higher than usual", according to the State Examinations Commission (SEC), which has apologised for the mistakes. Minister for Education Ruairí Quinn has received a report into the errors, which he is considering before issuing any comment.

The most significant error occurred on the Leaving Cert higher level maths paper 2, which gave the wrong value for an angle in a trigonometry question, making two different answers possible.

The SEC estimates that approximately 4 per cent of candidates – 521 of the 13,014 students sitting the exam – were adversely hit by the mistake.

The SEC says account was taken of errors during the marking process on all exam papers, and this ensured no candidate was put at a disadvantage.

The SEC issued examiners with a special set of instructions for correcting this paper, which involved developing criteria to identify affected scripts, applying a specific marking scheme to affected scripts, scrutiny of the scripts by a senior examiner, and a monitoring of the process, which included a comparison of scripts affected by the mistake with those which were not impacted. The full chief examiner’s report is expected in early 2014.

A total of 171 errors have been identified on Leaving and Junior Cert papers since 2009, although most of these were relatively minor.

Other more significant errors on the 2013 Leaving and Junior Cert papers included:

questions on the Leaving Cert ordinary level maths paper about material that was no longer on the syllabus. Speaking at the time of the exams, a spokesperson for the Irish Maths Teachers’ Association said there were more errors on this year’s paper than she had seen in 20 years.

an inaccurate description of the role of the Referendum Commission on the Junior Cert civic, social and political education (CSPE) paper.