Isaac Newton (1642–1727) was born in the tiny hamlet of Woolsthorpe in Lincolnshire in England. After attending the nearby King’s School in Grantham, he went to Trinity College, Cambridge University, where he avidly studied contemporary works such as a Latin edition of Descartes’s La Géométrie and a book of John Wallis on infinite series. Inspired by the latter work he produced, while still an undergraduate, the infinite series expansion for the binomial expression (p + q)m/n – not the finite version featured on the North Korean stamp, which had been known centuries earlier. Newton was later appointed Lucasian Professor of Mathematics at Cambridge, a post later held by Stephen Hawking. During the 17th century much progress had been made on the two branches of the infinitesimal calculus, now called ‘differentiation’ (finding the rate at which objects move or change) and ‘integration’ (finding the area enclosed by a curve). It was gradually becoming realised that these processes are inverse to each other – for example, integrating a function and then differentiating the result yields the original function. Around 1666 Newton investigated the rules of differentiation and integration and explained for the first time why this inverse relationship holds.

*[Dubai 1971; North Korea 1993; Russia 1987] *