Several factors have been blamed for an ongoing drop in the amount of New South Wales high school students signing up for top-level maths classes.

The Mathematics Association of NSW has analysed NSW Board of Studies and found the amount of students in senior classes has dropped 13 per cent over the last 12 years.

It says several things have been causing the decline, including the non-compulsory status of maths and the habit of many students to pick a lower level of maths to boost their tertiary admissions scores.

The Mathematics Association sought answers in a recent survey, speaking to over one thousands high school maths teachers about student participation and access to mathematically-qualified teachers.

Teachers say a key issue is the fact many maths classes are taught by teachers not specifically trained in the discipline.

The association says a shortage of qualified maths teachers has led to some cases where primary and secondary teachers have been teaching the subject in high schools, despite their lack of formal maths qualification.

They say around 80 per cent of maths classes between Year 7 and Year 10 should be taught by qualified teachers, but that is not currently the case.

“The results of this survey suggest the need for the development of a specialised Year 7-10 mathematics qualification, Dr Catherine Attard, president of the Mathematics Association of NSW, said.

Teacher also said some students have been choosing courses well beneath their capabilities to pump up their HSC and ATAR (Australian Tertiary Admission Rank) results.

But this means when the students actually get to university, they often have to take bridging classes to catch up on the higher-level mathematics they had missed.

There have been a number of suggestions for solutions, but no magic fix just yet.

A majority of those surveyed said universities should bring back high-level maths skills as prerequisites for relevant undergraduate degrees.