An Anglesey man who gave the world a mathematical symbol still in use today has been given a national day in his honour.
Mathematician William Jones, who grew up in Llanfihangel Tre’r Beirdd near Benllech, became the first person to use the Greek letter π (pi) to represent the ratio of the circumference of a circle to its diameter in 1706.
For the first time, March 14 has been designated Pi Day Cymru in his honour, and people are encouraged to celebrate maths and the contribution pi has made to the world.
The Americans have celebrated the day since 1988, and other countries have since followed suit.
The first three digits of pi are 3.14, which equates to March 14 in the American calendar.
William Jones’ only formal education was at a charity school in Llanfechell. His talent for mathematics was spotted, and it was arranged for him to work in a merchant’s counting house in London.
He served at sea, teaching mathematics on board Navy ships, where he became very interested in navigation.
As a result, he applied mathematics to navigation, studying methods to calculate position at sea.
Pi is an infinite number, and not even the most powerful computers have managed to calculate its exact value.
The idea for Pi Day Cymru came from another Anglesey man, retired professor Gareth Ffowc Roberts, who has now received the official backing of the Welsh Government.
This year is particularly special because the next two digits of pi are 15, and 3.1415 equates to March 14, 2015.
There are exact times during the day – 9:26 and 53 seconds - which correspond to the first 10 digits of pi: 3.141592653.
Professor Roberts said: “Because this happens only once every 100 years, it’s an ideal time for Wales to get involved and to remember our nation’s role in giving pi to the world.”
He urged schools in particular to undertake activities to mark the event and use social media to share what they are doing.
He added: “They might want to video themselves doing a pi memory test – in English or in Welsh, William Jones’ first language – or maybe young people could use pi to calculate the circumference of circular landmarks in their own localities.”
Huw Lewis, Welsh Government minister for education and skills, urged youngsters, teachers and parents to get involved.
He said: “Pi Day Cymru is an opportunity for people of all ages and walks of life to celebrate what pi has done for the world and to recognise Wales’ key role in developing the idea.
“Celebrating pi is about celebrating the value of maths and encouraging people to enjoy and make use of maths.”
