What is 34 + 17? Too easy? OK, how about 456 x 3?

These are pretty standard questions of the kind you’ll encounter in any numeracy test, so you might expect most of Britain’s brightest students to be able to answer them.

Yet when researchers from Queen’s University Belfast double-checked a couple of decades ago, they were in for a surprise. They gave some psychology undergraduates a set of similar questions and the students scored an average of only 53 per cent. In 2003 they re-ran the tests with the latest intake and found that far from rising, the average score had fallen to 41 per cent. It was a similar story elsewhere in Britain.

This is not a UK-specific phenomenon: something analogous has been