Recently released Trends in International Mathematics and Science Study results show a persistent rural-urban gap, and that students outside the major cities are lagging behind their overseas peers.

International tests like TIMSS provide much-needed health checks on our education system's performance. Around a year ago, the results from another test - the OECD-run Programme for International Student Assessment - sounded the alarm on collapsing achievement, most strikingly in maths.

By the age of 15, students at remote schools are two years behind their city peers. It's not hard to do the math on what that means for their opportunities in post-school education and work.

OECD research shows adults' confidence and competence with maths is a strong predictor of employment success - greater than any other single academic competency. Adults with high numeracy aptitude earn around 61 per cent more than those with a low level. And that's only becoming increasingly true.

Recently, the National Skills Commission announced that jobs with the best growth prospects, job security, and resilience to economic shocks, are in STEM fields. Common to all these jobs is strong foundations in maths. But while maths is used most intensively in STEM careers, all modern workplaces demand that workers can apply analytical, reasoning, and problem-solving skills to everyday tasks and decisions. Financial literacy - with applications at work and in daily life - is also closely correlated with maths achievement. In sum, no matter what field or occupation students go on to, being good at maths pays off.

However, for too many there's a complacent misconception that underachievement during school years can be easily redressed. But students who leave school without mastering maths rarely go on to pick it up. Remedial 'catch-up' and bridging courses for students preparing for post-school study are too little, too late, for those who've long struggled at school - with high failure rates and increasingly watered-down content.

That's why tackling low performance in maths at school is key to better preparing all young Australians for successful careers and further study. Yet, solving this particular equation requires tackling some of the most seemingly intractable of the school system's barnacles.

It's a poorly kept, decades-old secret that our teaching workforce lacks experienced and highly capable maths teachers - especially in the regions. TIMSS shows that just 16 per cent of Australian primary teachers have a maths background (compared to 66 per cent in high-performing Singapore). Outside the cities, that percentage is considerably lower. This is a limitation for students, not because their teachers can't keep up with the primary school standard, but because teachers who know and love maths better stimulate students' interest and curiosity from an early age.

The concerning disinterest and lack of confidence in maths can be seen in collapsing enrolments in senior secondary course choices - especially advanced courses. This feeds into insufficient university enrolments and completions in fields that aren't keeping pace with industry demand; meaning we must import highly skilled workers to fill vacancies.

One approach of policymakers is to make - or keep, depending on the state - maths mandatory for students until year 12, but this can backfire. Forcing more students to enrol in these classes - without the right teachers to make classes highly effective - can be a waste of time, money, and effort. And compelling uninterested maths students to take courses could result in yet further weakening of course content rigour - creating a downward spiral in standards.

The common denominator is the need for more, and more capable, teachers who specialise in maths - with market-based approaches the solution to overcome city-country gaps. Enabling more flexible entry to teaching is the most practical way to bring more mathematically-minded professionals into classrooms. Teachers who bring real world experience can help students better appreciate applications of maths and direct them to possible careers.

In addition to flexibility in teaching places is a need for more flexible pay for more aspiring teachers to make the switch. Salaries should be demand-based - so pay better matches market demand in subject areas of expertise - rather than fixed to years of service and other union-negotiated, one-size-fits-all, rigidities. Such supply-boosting approaches trump supply-restricting approaches that have been commonly applied - like setting arbitrary hurdles for potential teachers to meet accreditation.

Mathematical literacy is key to educational and employment success in the modern economy - for city and country alike. Without commitment to lift maths in the regions, we'll be counting the costs for years to come.

Glenn Fahey is education research fellow at the Centre for Independent Studies and was formerly a consultant to the OECD's Centre for Educational Research and Innovation.