Episode 4. On any plane separated into regions, the regions may be coloured in such a way that no two adjacent regions receive the same colour using no more than four colours. Read a history of the four colour theorem at the MacTutor archive or get more information on the theorem at Wikipedia.

On the podcast this week I sat down with Sarah Shepherd, a PhD student at the University of Nottingham and editor of iSquared Magazine and we talked through some maths stories that have been in the news. Links to all the articles we mentioned are below.

A new prime number has been discovered. Read “Huge new prime number discovered” on the BBC, or “Why 2 to the power of 43,112,609 – 1 = $100,000 for prime number hunters” from the Guardian. Find out more about the Great Internet Mersenne Prime Search (GIMPS), distributed computing software which uses volunteers’ PCs to search for prime numbers. Finally, the reward for discovering the new prime number is offered by the Electronic Frontier Foundation.

The stories about career changers into teaching and the golden hello are “Teaching maths adds up to a great career” from the Birmingham Mail and “Wanted: Maths teacher. £3,000 reward” from the Guardian.

The Ofsted report on maths teaching in England is “Too much maths ‘taught to test'” from the BBC and “Teaching style turns children off maths say inspectors” in the Times.

The reports on Maths Week in the Irish Times are “Magic, mosaics and Pythagoras promote maths for the masses” and “Author of maths books is a real stand-up guy”. You can find out more at the Maths Week website.

A review of the play “A Disappearing Number” is available on the Guardian website.

I mentioned Marcus du Sautoy’s The Story of Maths, for which the BBC4 Story of Maths page and Open University Story of Maths website have more information. The article on teaching maths in historical context by Marcus is “If maths is boring, what is the answer?” from the Telegraph.

Finally, I said there is good reading in Plus Magazine and iSquared Magazine.

Thanks to Sarah Shepherd of iSquared Magazine for joining me for this episode.

You can find out more about my work with the IMA by reading this blog and visiting www.ima.org.uk/student.