On average across OECD countries, students’ belief that they can solve mathematics problems (mathematics self-efficacy) is associated with a difference of 49 score points in mathematics – the equivalent of one year of school. There is a strong connection between how confident students feel about being able to solve pure and applied mathematics problems, and whether or not they were exposed to similar problems in class. When comparing students with similar academic performance and socio-economic status, those whose parents expected that they would enter university generally reported greater mathematics self-efficacy than those whose parents did not hold such high expectations for them.