Basic numerical abilities set the foundation for how the mind accomplishes the distinctly human task of understanding complex math. Theoretically, as math is a learned skill that builds on previously acquired knowledge, it is an ideal model for understanding complex learning. Practically, early mathematical competence is the single strongest predictor of later academic achievement and financial stability (Duncan et al., 2007; Romano et al., 2010). At the societal level, improving math scores is tightly linked with cross-national GPD growth (OECD, 2010). In direct contrast, low math ability is related to higher rates of mental and physical illness, unemployment and incarceration (Parsons & Bynner 2005). Critically, the mathematical performance of Canadian students on international math assessments has been on a steady decline since 2003 (Stokke, 2015) and in 2018, half of grade 6 students in Ontario failed to meet provincial standards for mathematics (Alphonso, 2018). Thus, studying the developmental neuropsychological underpinnings of mathematical thinking is not only intellectually fascinating but also practical – and urgently needed to understand and improve the worldwide debilitating effects linked to low math achievement.

In an uncertain global economy, skills in science, technology, engineering, and mathematics (STEM) are fundamental to Canada’s global competitiveness, economic growth, and overall standard of living (Council of Canadian Academics, 2015; Deming & Noray, 2018). Working in a STEM discipline is linked to higher earnings and a lower rate of unemployment (Arcidiacono, 2004; Carnevale, Cheah, & Strohl, 2013; Kinsler & Pavan, 2015). In Canada, the median yearly income for people working in STEM is $53,803 compared to $40,411 for those in non-STEM careers (Statistics Canada, 2016). Despite this high labour market payoff, our labour shortages are primarily in STEM disciplines (COPS, 2017; Deming & Noray, 2018, 2019; Randstad Canada, 2015). Also, significantly more men work in STEM than women, which is detrimental to women because jobs in STEM are among the highest-paying and fastest-growing occupations (Hango, 2013; Wall, 2019). Furthermore, diversity in the market labour force is known to strengthen innovation and performance (Phillips, 2014).