Is mathematics natural or man-made?

How US kids’ problems with fractions reveal the fascinating link between language and maths

Cast your mind back to your teenage maths lessons. Without a calculator, would you have been able to estimate the answer to the following sum? 12/13 + 7/8. Don’t worry about giving the precise number; just say whether it lies closest to 1, 2, 19, or 21*. By the end of middle school, most American pupils have been studying fractions for a few years; these questions should be embarrassingly easy. But when Robert Siegler, a psychologist at Carnegie Mellon University posed the problem to a group of 8th graders (13 to 14 year olds), he found that they performed little better than if they’d simply guessed – with just 27 per cent choosing the right answer. ….[READ]