We spoke to Coralie Colmez, mathematician and author of Math on Trial, about her genre-busting new Young Adult novel for mathematically minded teenagers: The Irrational Diary of Clara Valentine.

Tell us about your new book.

The Irrational Diary of Clara Valentine is a fun novel aimed at readers aged 15-19. It’s got all the good things in it: a mystery, a sharp-witted narrator, an idiosyncratic best friend, a couple of charming potential boyfriends, a mostly-loveable family, and some maths!

What inspired you to write it?

I first had the idea for the book around 10 years ago. My mother (a mathematician) and I had just written a popular maths book called Math on Trial, which was really fun to do, but it made me realise that I wanted to find a way to write about maths which was closer to the things I like to read myself, and I mostly read fiction. Following the release of Math on Trial, I got the chance to talk about it at events for students, which I really enjoyed, so I decided to write for that age group.

I found it easy to decide which maths topics I wanted to cover – they are all my own favourites, and the things that made me love maths when I was a teenager! The topics are quite abstract and high-level, like countable infinity and logic – things that would normally only be introduced at university, even though they don’t require much prior knowledge and I think high-school students would really enjoy learning about them.

I was also interested in writing YA because I felt that, while there is a lot of great YA literature, none of it looked like my own experience of teenagerhood. Characters are either off dealing with a fantasy world, with major emotional trauma, living an extreme life (Euphoria-style), or on the contrary behaving in a totally PG way. There is a space and a need for all of these types of characters, but I wanted to try and write ones that felt more real, and could have been my friends and me.

You’ve done a great job of including the maths naturally, as part of the story – did you find this difficult?

Thank you, and I am glad you think so! Because the topics I wanted to cover are quite high-level, I had to find some creative ways to include them. I got a lot of well-meaning publishing professionals suggesting that I have Clara solve problems involving measuring angles, calculating the length of a rope and that kind of thing, but I was really set on sticking with more abstract concepts.

I definitely wanted to make sure there were a few different ways that the maths became part of the story: some of it happens via the characters in the book that know maths at a high level, but we also see moments like Clara teaching her little sister something, or Clara’s best friend learning a bit of mathematical history in her philosophy class. That’s what it’s like in my family (which is made up of 50% mathematicians, so not entirely representative): maths is just a part of normal life.

I also wanted to include what it’s like to think about maths, so I really liked getting in Clara’s mind when she is solving a question: how she approaches problems from different angles – how some of these angles sometimes don’t work at all – and how amazing it feels to crack a problem.

Who do you hope will read the book?

I really think that anyone could enjoy the book. As a novel, it’s a pretty exciting read, it’s funny, and hopefully I’ve managed to capture a bit of today’s really exciting generation of young people, who are so sharp, aware and witty.

When it comes to the maths, it’s written so that readers of different levels can take what they want. Someone who has quite a high level of maths might even try to solve some of the problems along with Clara, whereas someone who only has a basic interest in maths might simply enjoy the overall concepts that are introduced, like realising how different ‘Infinity’ is to just ‘A really big number’. In terms of the level of the maths, I would say that an 18-year-old reader who already has an interest in maths might already have heard of 2 or 3 of the 8 topics covered, but hopefully they’ll see even the ones they already know in a fresh way, with some new anecdotes attached! A couple of the topics are included in the A Level syllabus, though most aren’t.

The book is aimed at readers all of all genders, but as a woman maths graduate – the only one in my year at my college – with a mathematician mother, it’s really important to me to encourage more girls into maths and science. I hope that having an awesome (if I do say so myself) female narrator like Clara can help with that.

Finally, age-wise, I wouldn’t recommend the book to younger readers, because there are some themes that might be too old for them, and there is some sex (which is entirely age-appropriate, at least if you are French, and also very positive for ages 15+) I’ve had some very lovely comments from older readers though, so I’m going to say that there is no maximum age to enjoy the book!

What made you decide to self-publish the book?

When I finished my first draft of the book, I actually found an agent very quickly, and there was immediate interest from publishers when she sent out the manuscript. I’ll be honest, at the point when I was talking to three big publishers at once, I thought I was about to be famous! But in the end, none of them wanted to publish exactly the book I wanted to write. One wanted it for a younger audience, another wanted me to focus just on the mystery, the third wanted me to first write a novel with no maths, as they were nervous about Clara being a debut. There was a lot of talk about which ‘shelf’ my novel would fit in, and I realised I didn’t want to write a book that just fitted on one shelf, because that’s not what life looks like! Clara cares about maths, about her relationships, about solving a mystery, about politics, about doing well at school… just like we all do (well, apart from the mystery maybe).

How can people get hold of a copy?

You can get a copy on pretty much any online retailer, like Amazon – or if you are avoiding Amazon, it’s on Waterstones if you are in the UK and Bookshop.org if you’re in the US, for example. I’ve also put the PDF on my website, so anyone can read it for free. The book is pretty though, and I’m quite proud because I designed the cover myself, so I’d recommend getting a copy!