My first foray into TV came in 2003 when I presented Inside Out Brazil, a five part BBC series about Brazilian art and culture. I also made two programmes about the Amazon, which I have linked to at the bottom of this page.

By the time I moved in to science popularization, YouTube had become an important part of the landscape. I have contributed to Numberphile - presenting its most viewed clip, a way of cutting a cake that I written about in Alex's Adventures in Numberland - and also produced my own videos. A selection are below.

I have written and presented documentaries about maths on BBC Radio 4, and have also appeared on various programmes including The Infinite Monkey Cage, the Museum of Curiosity, More or Less and Today.


YOUTUBE

This video I did with Numberphile on the best way to cut a cake has had 6.5million visitors.

Here's me talking about the number seven.

How to multiply using lines.

I presented this for Sky on the maths of publishing.


RADIO

Japanese children at an abacus club.

Japanese children at an abacus club.

Land of the rising sums

Why is it that Asian children perform better in international rankings of school maths ability than Western kids do? I travel to the All Japan Abacus Championship in Kyoto to find out and see one of the most incredible feats of mental arithmetic ever performed.

Listen here.

Nirvana by numbers

The number zero was invented in India one and half thousand years ago. I travel to India to investigate the links between this mathematical invention and the spiritual idea of nothingness. I sit with a guru in his temple and find the earliest zero written in stone. 

Shortlisted for best radio programme in the 2014 Association of British Science Writers Awards.

Listen here.

How to teach maths

I investigate how UK primary mathematics has changed in the last few decades, and the science – and politics – behind the changes. I explain new techniques like chunking and grid multiplication that leave many parents confused.

Listen here.


BRAZIL

My video diary of a road through the Amazon, originally broadcast on BBC Newsnight. Part 1.

I sailed down the river between Brazil and French Guyana on the trail of illegal goldmines. Part 1

The road remains unpaved 8 years later. It is still a big political issue. Part 2.

We found a mine and a mining town that's not on the map. Part 2.