students socioeconomic status explains of the variation in familiarity with mathematics within the country around of the students who have at least one tertiary educated parent reported that they know well or have often heard of the concept of linear equation on average across oecd countries only of students whose parents have only primary education as their highest level of attainment so reported similarly around of students with highly educated parents and only of students with loweducated parents reported that they know well or have frequently been exposed to the geometric concept of cosine