Cooking up a fresh approach to maths

Eugenia Cheng has her sights set on demystifying maths with the unique style of teaching she honed in Sheffield and which features in her book Cakes, Custard and Chaos Theory.
Eugenia Cheng has her sights set on demystifying maths with the unique style of teaching she honed in Sheffield and which features in her book Cakes, Custard and Chaos Theory.
Have your say

Grant Woodward meets the Yorkshire lecturer on a one-woman mission to rid the world of its maths phobia... with the help of a few homemade cakes.

EUGENIA Cheng is almost certainly the least likely maths teacher you could ever meet. For a start (with apologies to all the maths teachers out there, particularly the one that got me through my GCSE) she has a sense of humour – and a deliciously zany one at that.

A recent appearance alongside Daniel Craig on top US talk show The Late Show saw her pick up a rolling pin and engage in a spontaneous spot of fencing with host Stephen Colbert.

It was as though Douglas Fairbanks had been beamed on to the set of Ready Steady Cook.

But blessed with a boundless enthusiasm for just about everything, Cheng doesn’t really do dull.

And this playful approach extends to her teaching. A senior lecturer of Pure Mathematics at the University of Sheffield, she is unique in as much as she chooses to explain the most complex of mathematical theories through food. In fact, you could say she’s where pie meets Pi.

In her recently published book Cakes, Custard and Category Theory, Cheng starts each chapter with a recipe for a dessert. The idea is to illustrate the common strands between the methods and principles of both mathematics and cooking.

This linking of food and maths grew out of her early lectures at Sheffield. It’s all part, she says, of her mission to rid the world of its maths phobia.

Cheng wants to dispel the myths that the subject is only about numbers and whether the answer is right or wrong.

“I love food and I love maths,” she tells me, “but unfortunately most people love food more than maths.

“I’ve always liked telling unexpected stories to give more character and flavour to maths, and I realised that the ones involving food were particularly popular with my students, especially when it involved a demonstration.

“I started with a few demonstrations, and then each time I taught the same course I found myself adding some more.

“Once there was a plate of Oreo cookies on the front desk and nobody knew what it was doing there.

“A student said ‘Explain some maths with it!’ so I did, and then I found that I could explain almost any mathematical concept with a food analogy.”

In her book, Cheng touches on many of the challenges people are faced with when learning maths – from thinking you’re stupid because you don’t understand something to feeling demoralised when you keep getting the wrong answer but don’t know why.

She’s also keen to hammer home the importance of understanding the principle behind the process rather than simply memorising it – and that maths can be as fun, and easy, as making your favourite dish.

It goes without saying that Cheng is phenomenally bright. She studied at the University of Cambridge for both her undergraduate and postgraduate degrees and her specialism is category theory.

A branch of abstract mathematics often described as the “mathematics of mathematics”, category theory is defined as formalising mathematical structure and its concepts in terms of a collection of objects and arrows.

No, I’ve no idea either. But Cheng makes the case that “category theory is there to make difficult mathematics easy”. And her leftfield approach is catching on with students, maths enthusiasts and parents desperate for some way of getting their children enthused by a subject that, in the wrong hands, can be dry to the point of tedium.

Her Twitter feed is chock-full of food and maths mash-ups such as a graph charting her enjoyment of ice cream, while she has written a number of papers on the perfect quantity of cream for a scone and the ideal size for a pizza.

“Maths is a lot more like food than people realise,” she insists. “Both are really about putting some ingredients together in funny ways and seeing if the result is delicious or not.

“Pure maths is like the kind of recipes which only have a few ingredients but a very complicated method, like puff pastry.

“It’s much more about creating something and less about getting the right answer than most people think.

“Even if your puff pastry doesn’t come out the way you were hoping, it can still be tasty.”

Cheng credits her mother, Brenda, for nurturing her love of maths, casually making it part of everyday life.

It was she who encouraged her to cook too. After moving to the UK from her native Hong Kong, her mother forced herself to learn to bake as a way to assimilate into British culture.

Having been baking since three years of age, Cheng’s specialities now are brownies “or anything with chocolate in”.

“I think the fun part of cooking is when you start making up your own things, and the same is true of maths,” she says.

“It’s a shame that most people never get to that creative part, so I decided to write about it in my book.

“I hope that people will see that maths is not just about numbers, equations and getting the right answer. That it’s a way of thinking, and that its relevance is in the fact that we all think about things all the time, so being able to think more clearly is bound to be beneficial.

“Its relevance is not in calculating a tip at a restaurant or adding up your total at the supermarket. I hope that people will be less afraid of it.”

As for her barnstorming appearance on a major US television chat show which gained her a whole fresh bunch of fans, she says it was “great fun”.

She got host Stephen Colbert to help her beat butter and fold it into layers for puff pastry while together they tried to figure out the corresponding maths equations on a nearby blackboard.

As the pair concluded the segment by locking arms and eating some pre-prepared versions of the dessert, Cheng declared: “We made something delicious by the power of exponentials!”

In the space of a few minutes, Cheng had managed to get across a complex mathematical theory and leave the audience in stitches.

“It was exciting to see how excited everyone else was,” she says, “because my main aim in all this is to change attitudes towards maths, and the more people I reach the better.

“It’s also funny because deep down I still think of myself as the uncool young person who was much too geeky to be cool, but not geeky enough to fit in with the really geeky people, who sat around programming computers or talking about maths in their spare time.”

Though still affiliated to the University of Sheffield, Cheng is currently based in the US at the School of the Art Institute of Chicago, where she teaches maths to arts students.

At a time when a fifth of UK pupils lack basic maths skills, her offbeat approach could provide more than mere crumbs of comfort. And she has clear ideas how the teaching of maths needs to change to help youngsters to embrace the subject and kill off that maths phobia once and for all.

“The most important thing is to have good teachers who are excited about teaching the subject, and to give them enough autonomy to let them teach it in a way that suits them,” she says.

“Maths shouldn’t be about imposing rules on people, and nor should teaching. I also wish we’d stop pushing it on people as something that’s ‘useful’.

“Most people go through their daily lives without directly using any maths at all, so saying it’s ‘useful’ is at best misleading and at worst an outright lie.

“You can get through life perfectly fine without being able to add fractions or solve equations. Its ‘usefulness’ is in the way it trains us to think logically.”

Cakes, Custard and Category Theory by Eugenia Cheng is published by Profile Books, price £12.99.