Hi there, Toby Hendy! Why did you start making YouTube videos?

Toby: I have enjoyed watching YouTube videos since I was in school and it seemed natural to me to want to make my own videos as a way to participate in the community. The first videos I uploaded were a bit random, for example videos about kittens and sloths, but I soon started to focus on science videos.

How did you get so many subscribers?

Toby: I’ve been uploading videos to my channel ‘Tibees’ since 2011, so it has been a long process. It took me until 2018 to reach 100,000 subscribers and since then growth has been much faster. Choosing a niche helps, and I try to pay attention to memes and other internet trends that might bring in new viewers.

As a scientist and mathematician, did you notice any patterns as the number of subscribers went up?

Toby: There is a section of my subscriber growth that looks like it resembles an exponential curve. Once I found an audience it was easier to grow. Now my growth is a bit more steady but I do see spikes when particular videos become popular.

Do you pay much attention to the YouTube algorithm? Can you explain a bit about the maths behind it?

Toby: The YouTube algorithm is an infamously mysterious beast, but there are a few video metrics that the algorithm would consider when choosing which videos to display to users. One of these is the click-through rate, the percentage of users that click on a video when it is presented to them. If your click-through rate is high then the algorithm will show your video to more people and if it’s low then you might need to redesign the thumbnail or title.

Is there a magic number of times to publish videos a week? Or a certain length of video that always does well?

Toby: I don’t think there is any magic number, some channels do well publishing everyday and others publish only a few times a year. It’s similar with video length, in the end those decisions will depend on your audience and the kind of stories you want to tell.

Do you use maths in any other ways when making your videos?

Toby: There is a lot of maths that goes into researching and writing the videos especially when I cover topics from exams or the history of science. There are also opportunities to use maths and statistics to analyse a video’s analytics. Someone who can understand trends in data really well might be able to use analytics to improve a channel’s performance.

Your Joy of Mathematics videos are so great! Why is it important to present maths in creative and fun ways?

Toby: Mathematics can be a useful tool, but at its heart it is really a creative endeavour. For example, academic mathematicians need to develop new ideas in order to progress the field and these ideas come from playing with maths and treating it like an art. At the very least I hope that my videos help people to overcome “math-phobia”, and ultimately I would love to help more people see the creative side of math.

What do you love most about making maths videos?

Toby: I love that I am able to pursue topics that interest me and that I get to think about a variety of ideas, I try to cover something different for every video.

What’s your favourite video you’ve made?

Toby: I think my favourite video of mine is one called ‘Baking 4000 year old math’, where I recreate an ancient Babylonian multiplication table using gingerbread. I find it interesting to see how number systems have changed over time and was surprised that with just a few clues it’s possible to read math written 4000 years ago.

Any advice for those wanting to follow a maths career path?

Toby: There are a lot of great resources such as YouTube videos, blogs and books that reveal the creative and interesting side of mathematics which you might not have encountered in the classroom. I would advise people to spend time pursuing the ideas that interest them because you never know where it might lead.