Serious ongoing issues with children's mathematics results has experts pushing for radical changes to primary schooling, including the wide-scale introduction of specialist subject teachers.
That could mean the end of primary teaching as we know it, where one generalist teacher takes the class for every topic.
Maths scores have been declining since 2002, with National Standards figures showing one in four are behind in the subject by the time they leave primary school at Year 8.
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A national monitoring study from 2013 had even lower results, with just 41 per cent of students at the expected level when they leave primary, despite the majority achieving well just four years earlier.
The drop-off after Year 4 - when students are aged 9 to 10 - is a trend across all subjects, but in mathematics it is particularly significant.
"International studies and national data provide clear evidence that we have a serious achievement challenge in mathematics," a Ministry of Education maths plan said.
"We have very good evidence about what leads to effective mathematics teaching and learning. But putting this together in the classroom, and making it possible across the system, is challenging and complex."
A series of reports over the past decade have identified a range of underlying causes including teacher confidence and subject knowledge; decisions around professional development and training; and students' self-confidence and perceptions.
Professor John O'Neill, the director of Massey University's Institute of Education, called the problem a "chicken and egg" scenario.
Part of the problem is with NCEA, in that it allows too much choice. It's a very good system but it allows students to drop out of science and maths too early.
He said because many students dropped maths - and science - part way through high school, teaching students often lacked subject knowledge in those areas.
"In the past, you could fill students' gaps in learning at teachers' college. But whereas 10 years ago students would get several hundred hours in a learning area, now they might only get 50. It's not enough," he said.
Teachers then lacked confidence, their students got a raw deal, ended up not liking maths, and the cycle began again.
Some educators believed the answer was shifting teaching to master's level to raise entry levels, but even then graduates could come through with limited maths and science ability, Mr O'Neill said.
"Part of the problem is with NCEA, in that it allows too much choice. It's a very good system but it allows students to drop out of science and maths too early."
He said the Government needed to be "courageous enough" to recognise it would take the country 20 years, a sophisticated policy response and a long-term funding injection to break the cycle.
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The Ministry of Education had already added a suite of maths acceleration programmes and professional development to support underachievement in maths, at the cost of $20 million per year.
One is a 15-week intervention for struggling students, the other a programme that supports teachers to undergo extra training to become Mathematics Support Teachers over two years, during which time they work with small groups of high-needs pupils. They eventually help other teachers in their classrooms too.
The plan sent to NZME outlined further proposals to lift results, including restricting teacher entry to those with NCEA Level 2 maths. The Education Council is yet to decide if that will go ahead.
However, some believe an entry test alone will not be enough. A group of deans from seven universities have recommended teachers be required to undergo extra education in either English, maths, science or te reo Maori, with the view that subject specialty may become compulsory in the future.
NZME understands some deans believe the best way would be to have one subject specialist per school, or school cluster, who helped design interventions and build expertise among teachers.
Professor Stuart McNaughton, the Government's chief education scientific adviser, said he thought the better option was to have the experts teaching in classrooms after Year 4 - when evidence showed achievement growth slowed.
"My view is that we are requiring primary school teachers to cover too much, especially by the middle years," he said.
"These are very complex areas to teach and the question is whether our highly skilled and knowledgeable primary teachers can develop even more expertise across the board."
Mr McNaughton would not limit the specialist roles to mathematics, instead extending it to other curriculum areas especially te reo Maori and science.
A similar programme was under way in Singapore, where primary teachers are required to have a pairing of specialist subject areas as part of their teaching degrees from this year.
Principal of May Road School Lynda Stuart expressed reservations about the idea, saying that with just one teacher it was easier to reinforce learning across subjects.
"If you had a specialist for science who just came in the afternoons, for example, do they know what the kids have been learning in maths?" she said.
"The single-teacher model ensures a flow across the curriculum."
However, others also believe there needs to be an incentive to upskill a larger number of teachers in maths.
Associate Professor Roberta Hunter, from Massey University, said she supported a specialist qualification but it should be postgraduate level and needed to be available for teachers as well as new graduates.
Any training should also include cultural awareness, she said. Dr Hunter, who runs a cultural competency programme in maths, said many teachers weren't connecting with their Maori and Pasifika students.
Data showed a lag for Maori, Pasifika and low-income students, which widened as they headed towards high school.
Mount Maunganui has countered a nationwide drop in the number of students taking maths by encouraging female students to take the subject.
Principal of Mount Maunganui College Russell Gordon said he found the number of students in maths was "reasonably stationary", but the school had discovered most of the students dropping the subject were female.
"We undertook a study for 18 months to look at the reason for our young ladies not to take maths," he said.
Findings showed many students believed careers requiring math skills, such as engineering, were male dominated, which discouraged many females from pursuing maths at a higher level.
Mr Gordon said the school began encouraging more females to take the subject through mentoring and the appointment of female teachers in top-level calculus and statistics.
"The exciting thing is most senior classes are now a 50/50 split," he said.
President of the New Zealand Association of Science Educators and director of the House of Science Chris Duggan said many students began secondary school with a negative perception of science and maths.
"That's largely due to the fact there is so little science in primary, and kids assume they are no good at it because they haven't had the exposure or had that curiosity sparked in them," she said.
"Secondary teachers put a lot of effort into trying to get the kids up to speed ... and when they get to Year 12 and it's not compulsory to do science, kids drop it because they've had to, in those previous years, work extremely hard to try and get up to speed."
She said the perception that credits for science were harder to obtain than credits in some other subjects could also be contributing to the trend.
Ms Duggan said the House of Science was attempting to encourage children to "engage with science from a young age so they learned to put all those scientific thinking skills into practice ... They'd come into secondary schools with that curiosity well and truly sparked."
- Anna Whyte
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