A shortage of maths teachers is a key factor behind why students are receiving dramatically different amounts of teaching time in the subject, according to new research.
The report, Time in Mathematics Education, is the first of its kind to offer insights into the allocation of maths instruction time at second level.
It shows the time spent teaching maths differs dramatically across years, ranging from 120 to 300 minutes a week in first year, to between 180 minutes and 290 minutes a week in sixth year.
While the proportion of time allocated to maths is on a par with the OECD average, the report says significant differences across schools and teachers are a cause of concern.
The report finds availability of maths teachers as well as time-tabling constraints and its perceived importance as a subject are among the most influential factors in determining decisions on time spent teaching the subject.
This is despite national guidelines issued by the Department of Education on the instruction time that should be dedicated to the subject.
The research , by Niamh O'Meara of University of Limerick and Mark Prendergast of Trinity College Dublin, is based on a random sample of 400 secondary schools, as well as questionnaires of teaching staff.
It finds that almost two out of three teachers feel there is not enough time available to teach maths at junior cycle, while this rises to four out of five at senior cycle.
Most also say there has been no change in the time allocated to maths since the introduce of a new maths curriculum, known as Project Maths.
This is despite the fact that the vast majority of teachers feel the new curriculum requires more time.
Significant numbers of teachers said they were providing additional classes for maths on a voluntary basis in their own time, outside of school hours.
In its recommendations, the report proposes that students should receive equal amounts of maths instruction.
The report also says there is a need for a newer and sustained effort to increase the number of qualified teachers in maths and Stem subjects.
It adds that the time allocated in official syllabus documentation needs to be revised with more realistic guidelines offered.
In addition, it says one double period is needed for junior cycle a week, and two for senior cycle.