One in five adults (or 20%) has forgotten how to work out either fractions or percentages, and even fewer remember how to calculate the mean, the median or the mode, according to a study.
It reveals a perturbing lack of recall among many adults who have forgotten not just the rules of mathematics, but many of the key principles of English and science they were taught at school.
In maths, 35% of the 2,000 adults who took part in the YouGov survey said they would no longer know how to calculate the mode, 31% the median, 28% the mean and 27% the area of a circle.
Respondents were challenged by long division and multiplication, with a quarter unable to remember how to do the former and 23% the latter. Meanwhile, 26% had forgotten how to work out the square root.