Prior research on educational, numeracy, and wage gaps tends to focus on highincome, countries. However, achieving the United Nation's Sustainable Development, goals for education and gender equality requires focusing on middle-income countries., In this study, we examine gender gaps in educational attainment, use of numeracy skill, in the workplace, and wage inequality in 12 middle-income countries. By analyzing, data from the World Bank's Skills Toward Employment and Productivity (STEP) study, we find that educational attainment explains differences in numeracy skill use, as well, as independently influences the gender wage gap. Our analyses also indicate that in, four countries examined in this study, a one-unit increase in women's engagement with, numeracy tasks is positively correlated with a 5% increase in women's wage. In, addition, this study suggests that unlike in the OECD, in these middle-income countries, investigated, the roots of gender wage gaps lie in forces even before women entering, the labor market. In the context of Sustainable Development Goals, this paper provides, new evidence about the importance of improving gender equality in education and, skills across middle-income countries to fulfill SDGs 4 and 5.