It is no secret that disadvantaged children are more likely to struggle in school. For decades now, public policy has focused on how to reduce the achievement gap between poorer students and more-affluent students. Despite numerous reform efforts, these gaps remain virtually unchanged--a fact that is deeply frustrating and also a little confusing. Does this mean that schools can't effectively address inequality? One of the key factors driving inequality in schools is unequal opportunity to learn (OTL) mathematics. In previous articles for "American Educator" and elsewhere, the authors define OTL as the important yet often overlooked relationship between mathematics performance and exposure to mathematics content. They explain here that it is very unlikely that students will learn material they are not exposed to, and there is considerable evidence that disadvantaged students are systematically tracked into classrooms with weaker mathematics content (e.g., basic arithmetic taught in a so-called algebra class). Rather than mitigating the effects of poverty, many American schools are exacerbating them. Specifically, the latest PISA data find that: (1) There is large variation in exposure to mathematics content; (2) OTL is strongly related to student performance; and (3) Lower-income students are generally exposed to less-rigorous math. It's not just that lower-income students are less well prepared when they enter school; the weakness of their math coursework actually keeps them from catching up. What is truly fascinating about the PISA results is that this is a "global phenomenon." In every country, more exposure to formal math content was related to better math performance, and almost every country showed a statistically significant relationship between student socioeconomic background and OTL. In other words, the problem the authors identified in the United States turns out to be a problem everywhere. The authors posit that these findings should make American educators reconsider their approach to education reform. Educational inequality is not a U.S.-specific problem, but some education systems do a much better job than America does in coping with the effects of poverty. More important, the math content that is taught in the classroom plays a critical role--a fact that has received far too little attention and one that is examined here.