TO BE awarded, after competition, one of the most prestigious prizes that the University of Cambridge can offer must be a crowning moment for every good young mathematician. And so it was for Martyn Cundy, who took the Rayleigh Prize in 1937 for his essay Motion in a Tetrahedral Field.

Cundy’s contemporaries were men such as Alan Turing, Harry Pitt and Fred Hoyle, all future Fellows of the Royal Society. With his background of distinctions in higher certificate in mathematics, divinity, Latin and Greek, and a starred examinee in part III of the mathematical tripos in 1935, Cundy might have been expected to take an immediate research fellowship at Trinity. Instead, he went a year later to Sherborne School, to teach mathematics. And so he became, gradually, the greatest teacher of the subject of his generation.

Even in the golden interwar years of education when it was still common for those with good first-class degrees to go into the grammar schools and the better independents, it was astonishing that a Rayleigh prizewinner should do so. But if Cundy was a loss to university mathematics, he was an even greater gain to schools.

Born in 1913, he must, as a boy, have picked up his deep Christian faith from his priest father who even named him after a forebear — the missionary Henry Martyn who had been Senior Wrangler in 1801. So at Cambridge, on becoming secretary of the 1934 Cambridge Prayer Fellowship, he began an active life of Christian witness. In turn, he was a Methodist lay preacher, the author of The Faith of a Christian, an elder in the Malawi Presbyterian Church, a lay reader in Kendal (and organist), and winner of the Diocese of Carlisle 850th anniversary hymnwriting competition.

Each year his friends received a Christmas card with a delightful line drawing and a brief Nativity verse. His excellent personal relations must have been at least partly due to the serenity and composure which went hand in hand with his spiritual strength.

He first came to the notice of the wider mathematical community in 1951 with the publication of Mathematical Models, jointly with A. P. Rollett. Still in print, this book became an inspiration for generations of mathematics teachers. But throughout his life there poured forth a continuous stream of at least 50 delightful and erudite articles published in the Mathematical Gazette.

It was typical that many were based on some everyday artefact. But many others revolved round his fascination with triangles and their associated lines, circles and cubic curves. Such a paper in 2003 was voted Article of the Year and the last, published at the end of 2004, contained what must be the most complicated geometrical figure ever printed — and that despite the failing eyesight which distressed him in later years. More substantial research papers were published in the Journal of Geometry.

In 1961 there came the opportunity to exert a decisive influence on school mathematics. Three heads of mathematics — Tom Jones, from Winchester, Douglas Quadling, from Marlborough and Cundy, from Sherborne — met, largely at the instigation of Bryan Thwaites (then a professor at Southampton and now Sir Bryan) to consider new syllabuses at O and A level. They were an exceptional trio, and it is hard to imagine that such a powerful group could be formed nowadays from schools. They were hugely ambitious in their plans, which included not merely new content but the writing of new, and novel, texts and teachers’ guides, together with a large continuing programme of residential teacher-training courses.

As more teachers became involved, a formal organisation was created: the School Mathematics Project. The SMP (as it became known) rapidly became the dominant player in the reform of school mathematics and its influence spread internationally, most notably in Africa. It is the only project of those heady years of curriculum reform in the early 1960s that still operates.

In this great and complicated exercise Cundy played a hugely influential role in two respects. First, his profound knowledge enabled him to see mathematics in the round. There were connections between geometry and calculus and algebra which could be explored to the great advantage of the texts and which could kindle the interest of pupils.

His own writing was always of the highest quality, clear and concise, and his tactful comments on the writing of others were always gratefully received. He edited both volumes of Advanced Mathematics (1968), which many would say were the finest sixth-form texts written.

He exerted a quiet influence within working groups. The SMP necessarily spawned committees and planning meetings of all sorts. But Cundy was no committee man in the bureaucratic sense. Instead he was the great conciliator. He would look around an argumentative group without taking much part and simply make some quizzical remark which would not only suggest a solution but also settle tempers. Nevertheless, he was for a time deputy director and an initial trustee when the SMP became a registered charity in 1967.

The SMP’s growing involvement in overseas education led Cundy to the chair of mathematics in Malawi in 1968. His latent missionary zeal no doubt played a part in his decision to help the fledgeling university which was to move in 1973 from Limbe, near Blantyre, to Zomba, and he threw himself with gusto into its development.

Mathematics may have been his first responsibility there, but he was also involved with other matters such as student housing, staff welfare and provision for religious worship. He had little difficulty in responding appropriately to local culture and customs, learning the local language Chichewa on the way.

He was admirably supported by his wife Kittie, whom he married in 1939. She was a mathematics student at Cambridge where they first met.

Cundy had a love affair with mountains, so he and Kittie took a special joy in walking the great African spaces. Their many guests from the UK were almost invariably offered a couple of days high on Mount Mulanje, the wonderful granite inselberg immortalised by Laurens van der Post in his novel Venture into the Interior. Nearer home was the Zomba plateau, for which they wrote and published a walkers ’ guide. And it was typical of Cundy’s approach to mathematics that he composed an A-level question based on his observation of the plateau’s afternoon shadow moving on the plain below.

The couple returned to Britain in 1975. After a brief stint in the Caribbean for the British Council, they settled in Kendal so as to be members of a lively church encompassed by mountains. There followed nearly 30 years of wideranging activity during which he always gave more than he received.

Cundy was a man of huge talent and influence, beloved and respected by all who knew him and greatly admired by so many who did not. His bequest, with Kittie, spans their two chief interests, Christianity and mathematics, for two of their sons were heads of mathematics and the other is Bishop of Peterborough.

Martyn Cundy, mathematician, was born on December 23, 1913. He died on February 25, 2005, aged 91.