Snacking on Math Videos

What is this post about?

Why do I (want to) make math-sy YouTube videos? And why do people watch them? These are the questions I would like to answer today. I have been thinking about my motivations for making math animations for a while now and this tweet (x?) by Andrej Karpathy plus a recent conversation with a friend finally aligned my incoherent thoughts into a coherent answer.

Why do people watch math videos?

First, why do people watch math videos? I wouldn’t be surprised if your answer is that it’s because they like to learn. And watching math videos counts as learning. Right? Well, noooot really. Watching math videos is not really learning. Learning requires effort and discipline. It’s an activity that you need to push yourself to do because you know it’s good for you. Learning is like eating carrots, watching math videos is more like candy. Of course you can argue that math videos are the bio-vegan-low-sugar type of candy when compared to something like scrolling TikTok. But nevertheless, it’s a snack, not a meal.

Take for example my most popular video. It’s a 2 minute 37 seconds long snack. And if you look at the retention graph, most people actually started to drop-off at the 33 second mark. That’s exactly the point where I just finished introducing the math-thing that this video was about. Without yet actually providing any math. So most people that clicked on this video have considered it a snack. They have learned that this fun math think exists but that’s about it.

However, there is a small group of viewers that actually learned something by watching this. You might be tempted to think that this group is the 18% of people that got all the way to the end. But I think the real number is even lower than that, probably less than 1%. The people that have actually learned something by watching this, are the people who took out their pen and paper and spent some time trying to proof the geometric contraption I’m showing in the video. It’s the people who then went on to comment alternative proofs for why this fun math trick actually works.

Retention graph

So why do people watch math videos? Mostly for entertainment. But this brings up another question. Are people who watch math videos aware of the fact that they are watching for entertainment? Or do they think that they are watching and actually learning something? I think the latter is the case for most of the viewers. They are watching, thinking that they are learning something, maybe even thinking that they are better than others who simply scroll TikTok. And you know what, they probably are a bit better. They at least have a longer attention span. But it’s still entertainment. And I think that should be made clear. Not necessarily by the creator but rather by the viewer. There should be a clear intention behind opening yet another math video. A binary switch in your head that either says: entertainment or learning. If it says entertainment, you sit back, relax and watch, knowing that you are not actively learning. Nothing wrong with that. We all need rest and entertainment. But if it says learning, you first of all probably watch a slightly less flashy video than a 3b1b style explainer and secondly, you stop frequently, write down notes, solve some toy examples on a piece of paper and actually put in some effort.

Why do people make math videos?

Where does this leave me, the creator of math videos? I think the creator should be thinking about why? their audience is watching. Or rather, they should decide which intention do they want to satisfy for the viewer - entertainment or education. And although this seems like there are only two paths forward, I think there are actually at least three angles to play into here.

Option 1: Entertainment

Make videos purely for entertainment purposes. This doesn’t mean just jokes and drama but rather good storyline, nice animations, sound effects, bird’s eye view explanation etc. Think of Veritasium or SciShow.

Option 2: Education

Make videos for education only. This means lectures. Lowkey boring but full of information. For the person that’s actually sitting on the other end with a pen and paper or with an open code editor and it’s putting in the work. Brain circuits running full speed. Think Khan Academy.

Option 3: Spark

And lastly, I think there is a third option. I call it spark. As in: spark the interest of the viewer to go on their own and make their brain circuits burn. This is the type of videos I aspire to make. An explainer that excites and makes you curious to go and learn more. A little invitation to the dark side of putting in some work and actually learning something new. It differs from Option 2 in two ways: First, the viewer would not intentionally search for it, and second, it is not as nitty-gritty as a full-fledged lecture. It also differs from Option 1, but the line here is a bit blurrier. I think the key differentiating factor is the intention with which the video is made. Let’s take my Matrix Tree Video as an example. I decided to make this video, because I personally derived great joy from the process of trying to understand this theorem and I wanted to allow others to experience this as well. But if I just explained it all, it would become entertainment and it would not provide the same joy as putting in the work and getting those aha moments along the path to understanding. That’s why I made a little animated movie that introduces the seeming impossibility of this theorem which I hoped would spark some of the viewers to dig deeper, and discover the full nitty-gritty details on their own. To do that, I also wrote an accompanying blog posts, that sketches out the nitty-gritty details and provides even more resources so you have a wide variety of materials to learn from on your own.


Next time you watch another math video, set your intention clear and stick to it. It’s fine to do it for entertainment, but be aware that you are doing it for that purpose. And as for myself, my intention is clear: spark that curiosity and provide resources to fulfill it.