Tom Rocks Maths S02 E11

A special edition of Tom Rocks Maths on Oxide Radio with music inspired by Tom’s recent visit to Slam Dunk Festival. We’ve also got Pokemon and drinking games, a mind-bending Einstein Puzzle, and news of Tom’s antics running around the streets of Oxford in his underwear… This is maths, but not as you know it.

Blueprint Interview

Interview with the University of Oxford’s Blueprint magazine about my mission to popularise maths and my outreach work with the St John’s Inspire Programme. The full interview with Blueprint’s Shaunna Latchman can be found in the online magazine here.

While some avoid arithmetic at all costs, Tom fully immerses himself daily teaching maths to the first and second year undergraduate students at St Hugh’s College. He also arranges activities for St John’s College as the Access and Outreach Associate for Science, Technology, Engineering and Maths (STEM) for the Inspire programme. Another activity is planning and filming content for his own outreach programme – Tom Rocks Maths.

‘It was the subject that felt most natural to me’, explains Tom, who first realised his love for numbers aged seven when his class had been set ten long multiplication questions. He raced through the whole book. However it wasn’t until he received ten A*s in his GCSEs that he began considering an Oxbridge education. ‘Academically there isn’t much of a difference [between Oxford and Cambridge]’ Tom comments, ‘but Oxford felt more like home.’

Later, after completing his PhD in Applied Maths at Cambridge, he was offered an internship with public engagement team, the Naked Scientists. The group strip back science to help make a complicated theory easy to digest. Weekly podcasts are broadcasted through BBC Radio 5 Live and ABC Australia, where audiences reach up to one million listeners a week.

Tom saw an opportunity to bring his appreciation for maths to the masses, but he wanted to do it with a twist. Eager to move away from the stereotypes of maths being a serious subject taught by older men in tweed jackets, he thought ‘what is the best way to make maths less serious? Doing it in my underwear!’ And so, the Naked Mathematician was born.

Since joining St Hugh’s, Tom continues to break down day-to-day activities on his YouTube channel to prove that maths is an integral part of everything we do.


His passion for engagement doesn’t end there. The Inspire programme, part of the Link Colleges initiative, is a series of events, visits, workshops and online contact for pupils in years 9 to 13. Tom works with the non-selective state schools in the London boroughs of Harrow and Ealing.

The Link Colleges programme simplifies communication between UK schools and the University. Every school in the country is linked with an Oxford college, with the hope that this connection will encourage students to explore the possibility of attending university.

‘The aim is to have sustained contact with the same group of students over five years,’ says Tom. ‘There are still students who haven’t thought about university, or maybe it’s not the norm in their family or area to attend university. So, we explain what it is, how it works and the positives and negatives. We want to inform and inspire them.’

Tom is responsible for arranging all STEM events across the year for 60 students in each year group. He calls on the expertise of his colleagues at Oxford as well as encouraging a partnership with the University of Cambridge and several universities in London. ‘The syllabus includes various topics such as the science of food and using maths to improve diet.’

During Tom’s famed Maths vs Sport talk, students are encouraged to participate in an on-stage penalty shootout – but only after learning about the mathematical makeup behind such a pivotal moment in a football game, of course.

Tom believes maths is made more accessible by relating it the world around us. He encourages his students to question things, like why bees make hexagonal shapes in their hives and how many Pikachus it takes to light up a lightbulb.

Whether visiting schools up and down the country to deliver talks, recording the weekly dose of Funbers for BBC radio – fun facts about numbers that we didn’t realise we secretly wanted to know – or in front of his class of students, Tom is certainly making waves in the world of maths.

Pokémaths: how many Pikachus does it take to power a light bulb?

The mascot of the Pokémon world and probably the most famous of all the Pokémon: Pikachu. It’s pretty much just a short, chubby rodent with two red circles on its cheeks that it apparently uses to store electricity. So the obvious question to ask here then is how many Pikachus would it take to power a lightbulb?

The official Pokédex tells us that Pikachu is able to ‘release electric discharges of varying intensity’ and is also known to ‘build up energy in its glands that needs to be discharged to avoid complications’. Quite what these ‘complications’ might be I’m not sure – suggestions on a postcard. The Pokédex also says that the tail of a Pikachu plays an important role as it acts as a grounding rod to prevent the creature from electrifying itself and also allows one Pikachu to recharge another one that’s running low on juice. Another fun fact about Pikachu’s tail is that a female will have a v-shaped notch at the end which is not present on males. Next time you’re out Pikachu hunting, now you know.

When a Pikachu uses its signature move, thunderbolt, it releases 100,000 volts of electricity. You might think that this would be enough to kill you, never mind just power a lightbulb and you wouldn’t be wrong, but there’s a little more to it than that. When someone dies from electrocution, it isn’t the voltage that kills them, it’s the current. If a current of just 7 milliamps reaches your heart for around 3 seconds its lights out. The current is tiny, but it disrupts the hearts natural rhythm causing it to stop. You can of course be electrocuted and live to tell the tale, but this means that you were very lucky in that the path that the electricity chose to take through your body must have avoided your heart. In general, electricity will flow along the path of least resistance, as with most things in nature it’s lazy and so takes the path that is the easiest.

I’ve now mentioned three terms, which means a good old fashioned physics formula triangle. The particular one we want here is Ohm’s Law:


The resistance of your body is around 100,000 ohms, which means thunderbolt generates a current of 1 amp that will flow through your body. In other words, if it hits your heart you’re toast.

Now onto lightbulbs. They come in all sorts of different shapes and sizes, and different amounts of wattage or power. The standard one is 60 watts and that’s the one we’re considering here. None of these fancy energy saving bulbs that start off really dim so that you can’t see a thing and gradually build up in brightness… (don’t get me started on them). The key bit of physics that we need relates power (in watts) to Ohm’s Law above and states:


For a 60 watt light bulb attached to the UK mains supply of 230 volts, this generates a current of 0.26 amps. If we were to connect the bulb up to a Pikachu using thunderbolt the current decreases hugely to only 0.0006 amps. The light bulb will still work but the current will just be very small. This means only a small wire is required and also has the added benefit of reducing the chance of electrocution… However, 0.0006 amps is still enough to kill you if it hits your heart, so be careful next time when you’re hooking up your lightbulb to a Pikachu!


All of the material in the Pokemaths series can be found here.

Up ↑