A Review of Khan Academy

My review of Khan Academy for learning math and programming.

Khan Academy is an American non-profit organization launched in 2008, created by Salman Khan. As an Indian, it is so odd to type this, for Salman here doesn’t have much to do with education… never mind, moving on.

The site offers videos and practice lessons, and during covid times, it was an invaluable source for teachers and students alike. If you go to its Wikipedia, you will get some impressive numbers right off the bat about this platform, mainly the YouTube subscribers which number more than seven million, and the YouTube videos have been seen around two billion times.

Though Khan Academy teaches a wide variety of topics, from sciences like chemistry and physics, to humanities topics like history, it started out with math, and branched off later. And in this review, I will be focusing on math and programming parts.

Since I’m blind, learning math is hard for me. If you wish to understand some of the context below in more detail, then read this article on my other blog, where I talk about ways I have tried to learn math, including Khan Academy.

A note before we start this review. You might think that Khan Academy is not for adults, but that is not true. No matter what your age is, you can use this platform for learning whatever you like.

So, how is Khan Academy for learning math?

Let’s talk about the range covered first. From early math from kindergarten level, where you can learn to count, to college-level math with calculus and statistics, you can find it here. So the range of material is good. Though I often times found myself miffed that discrete math is not covered here differently, given how it is necessary for the computers.

The videos are good, and if you have sight, then they are invaluable for explaining the concepts quickly and succinctly. But for me, they were not good enough. I often struggle to keep up with videos, but this is nothing unusual. Blind people struggle with learning from video. I am nothing unique in this regard.

However, I was more interested in the exercises. The math has a huge collection of topics, which are divided into smaller topics. For example, in arithmetic topic, there is a topic about 1-digit multiplication, which has lessons like multiplying with 1 or 0, and apart from video lessons, a practice lesson where you get questions where you must supply the right answer. It sort of reminded me of Duolingo in this regard.

These sub-topics, called units, have a way of measuring your progress. Each time you perfect the practice exercises, you get points. Fifty points if you answer every question with just one mistake, while 80 maximum points if you answer all the questions without a mistake. After you complete a certain section of a unit, you will also see quizzes, but these quizzes only offer points if you have not perfected the lessons above.

Once you complete a unit, you can try the unit test, which will test you on every topic of the unit, and this is where you can get the remaining points. If you already have 80 points on some practice skills, and you answer all the questions in the unit test for that skill without a mistake, you will get the remaining 20 points, and the skill is considered mastered. There are achievements which are called badges, which depend on you mastering a certain amount of skills. For example, Sally Ride, which is achieved when you master 150 skills.

Now, these exercises are good for a blind learner like me, since I can get the theory from somewhere else since videos are not good enough for me, and apply the theory here for practical experience. But this isn’t perfect. The problems range from pedantic to serious. Let me present an example.

Here’s a problem taken from the skill add within 20, which asks you to perform addition on the numbers below 20.

equals, start color #0c7f99, 14, end color #0c7f99, plus, start color #ca337c, 3, end color #ca337c

We are asked to find the unknown value, which we can do by adding 14 and 3. But do you see the gibberish text around those numbers? I know enough of my html that color-codes can be used instead of the color name. And I also understand why the numbers are color coded, but for a screen reader user like me, parsing that gibberish is hard. Sometimes when I do some complicated math problems with multiple parts, I get confused with numbers as well. And this thing is not just limited to one skill. No, this is true for every skill.

I suppose if you get enough experience with using a screen reader, you will get past this problem, though you will be annoyed as hell when your answers are not right, and you have to read everything slowly. But there are other problems. I wouldn’t be able to give examples of them all, but I will do my best to describe them.

In certain skills, the questions require you to observe a diagram and then answer it. This isn’t accessible with screen readers, not completely at least. Diagrams are one thing, but sometimes you have to look at an image, and then give an answer to it. If the image has captions, then fine, I can try my hand at calculating something, but my accuracy will be horrendous. But sometimes, I encounter a skill where all the questions have images without captions, and naturally, I am unable to even try them. This mostly happens with geometry, but it is also prevalent in other units and skills.

When they are not color coding the numbers, Khan Academy uses MathJax to render math much like everywhere else on the internet. But MathJax has problems, in particular, you need to get some out-of-date and unsupported software with NVDA to make it read that, though JAWS seems to be able to read it just fine. However, reading initially is very slow, and it can also end up crashing the page sometimes.

Even if you managed to get NVDA read MathJax, you will have to deal with it carefully. It tends to read everything out in one line like this:

1 + 3 line 1, 4 line 2.

Now, these problems can be dealt with. But what cannot be worked around are errors. If there is an error, then instead of a number or an equation, you’ll get to hear the wonderful phrase “MathML error.” And there is no salvaging that one.

My final problem is, the difficulty is wonky. Take the example of a unit of negative numbers. You might think that since you haven’t dealt with signed numbers yet, you’ll get some simple integers to work your muscles on. But no, you are thrown into the deep end with fractions and decimals popping up at random in the skill questions.

I searched around, and found out that Khan Academy uses their custom solution for accessibility. I tried to reach them with my complains, offering myself to test these problems, but I never got past their captcha system, and trying to reach them over Twitter resulted in nothing.

Having said all of that, for now, I think Khan Academy is the only good place to practice math. You will have an easier time if you have two working eyeballs, but if you’re blind, then be ready to encounter some difficulties.

How is Khan Academy for learning programming?

I may come off as overly critical above, but overall, I had a pleasant time learning math from Khan Academy. I have not found any better site on the internet for that.

However, programming is problematic. First, videos are not good; again, unlike math, I couldn’t even bring myself to sit through and finish a single video.

Second, they use processing.js, which is now outdated, and is not supported anymore. But I don’t think it is a huge problem for someone who is just starting out.

But they do teach outdated JavaScript practices, like the use of var everywhere. I kind of get the feeling that this course has not been updated in a long while.

The editor is a problem for me to use. Now, I have tried my hand on other coding-related sites, and I have seen how even an online editor could be inaccessible with a screen reader. But at least, they allow me to copy the code, paste it offline, and then paste the modified code back inside.

But Khan Academy’s editor doesn’t let me do that. I get the reasoning; typing the code by yourself gets down to the concepts faster. But here, this literally went against me.

Even though they used visual concepts for teaching, for example, drawing a snowman, I actually liked their feedback. If I make a mistake in values, I get these helpful messages where I realize which values I should modify to draw the right proportions. It is kind of like working with Lisp, accepting the Lisp giving you an idea of how you can draw the necessary thing with modifying the right values. (As far as I have read about Lisp language, I have no direct experience with Lisp… yet.)

I still wouldn’t be able to draw graphics, true. But I really do think this was a great way to teach.

Unfortunately, it is all spoiled by the editor. I couldn’t bring myself to deal with it any further, so I never got around to the SQL part.

If you’re sighted, and do want to learn programming for the first time, I suppose you can try Khan Academy for it. But as a blind person? Stay away. Unlike math, it is not worth it to deal with the headaches of their editors.

If I ever get around to learning physics, I’ll write about my experiences here as well. If you like my review, then please consider buying me a coffee to support me. follow this blog for the latest updates, and I will see you in the next article.