There is practical mathematics, which provides the calculations that sustain just about every industry including the finance sector, and the mathematical sciences sector is said to be worth almost £500 billion to the UK economy. And then there is pure mathematics, where in the words of the Greek historian Plutarch two millennia ago, “there can be no reference to the vulgar needs of life”. It is a world of abstract structures, amidst which exploring the nature of numbers themselves is the purest of the pure.

Prof. Minhyong Kim, the director of the International Centre for Mathematical Sciences in Edinburgh, is one of the world’s leading number theorists. He is also the author of nine popular books about mathematics, several of which have become bestsellers in his native South Korea; his latest one is a colourful cartoon adventure for children. One of the Centre’s new projects is Mathematics for Humanity, aimed at supporting projects in mathematics that help to make the world a better place. He describes what a pure mathematician does and why.