What’s the essential skill of a cartoonist? Drawing ability? Humor? A deep well of childhood trauma?

I’d say it’s an eye for simplification, capturing the essence of an idea.

For example, let’s say we want to understand Ed O’Neill:

A literal-minded artist might portray him like this:

While the technical skill is impressive, does it really capture the essence of the man? Look at his eyes in particular.

Wow! The cartoonist recognizes:

The unique shape of his head. Technically, his head is an oval, like yours. But somehow, making his jaw wider than the rest of his head is perfect.

The wide-eyed bewilderment. The whites of his eyes, the raised brows, the pursed lips – the cartoonist saw and amplified the emotion inside.

So, who really “gets it”? It seems the technical artist worries more about the shading of his eyes than the message they contain.

## Numbers Began With Cartoons

Think about the first numbers, the tally system:

I, II, III, IIII …

Those are… drawings! Cartoons! Caricatures of an idea!

They capture the essence of “existing” or “having something” without the specifics of what it represents.

Og the Cavemen Accountant might have tried drawing individual stick figures, buffalos, trees, and so on. Eventually he might realize a shortcut: draw a line and call it a buffalo. This captures the essence of “something is there” and our imaginations do the rest.

Math is an ongoing process of simplifying ideas to their cartoon essence. Even the beloved equals sign (=) started as a drawing of two identical lines, and now we can write “3 + 5 = 8” instead of “three plus five is equal to eight”. Much better, right?

So let’s be cartoonists, seeing an idea — really capturing it — without getting trapped in technical mimicry. Perfect reproductions come in *after* we’ve seen the essence.

## Technically Correct: The Worst Kind Of Correct

We agree that multiplication makes things bigger, right?

Ok. Pick your favorite number. Now, multiply it by a random number. What happens?

- If that random number is negative, your number goes negative
- If that random number is between 0 and 1, your number is destroyed or gets smaller
- If that random number is greater than 1, your number will get larger

Hrm. It seems multiplication is more likely to *reduce* a number. Maybe we should teach kids “Multiplication generally reduces the original number.” It’ll save them from making mistakes later.

No! It’s a technically correct and real-life-ily horrible way to teach, and will confuse them more. If the technically correct behavior of *multiplication* is misleading, can you imagine what happens when we study the formal definitions of more advanced math?

There’s a fear that without every detail up front, people get the wrong impression. I’d argue people get the wrong impression *because* you provide every detail up front.

As George Box wrote, “All models are wrong, but some are useful.”

A knowingly-limited understanding (“Multiplication makes things bigger”) is the foothold to reach a more nuanced understanding. (“People generally multiply positive numbers greater than 1, so multiplication makes things larger. Let’s practice. Later, we’ll explore what happens if numbers are negative, or less than one.”)

## Takeaways

I wrap my head around math concepts by reducing them to their simplified essence:

Imaginary numbers let us rotate numbers. Don’t start by defining

*i*as the square root of -1. Show how if negative numbers represent a 180-degree rotation, imaginary numbers represent a 90-degree one.The number e is a little machine that grows as fast as it can. Don’t start with some arcane technical definition based on limits. Show what happens when we compound interest with increasing frequency.

The Pythagorean Theorem explains how all shapes behave (not just triangles). Don’t whip out a geometric proof specific to triangles. See what circles, squares, and triangles have in common, and show that the idea works for any shape.

Euler’s Formula makes a circular path. Don’t start by analyzing sine and cosine. See how exponents and imaginary numbers create “continuous rotation”, i.e. a circle.

Avoid the trap of the guilty expert, pushed to describe every detail with photorealism. Be the cartoonist who seeks the exaggerated, oversimplified, and yet *accurate* truth of the idea.

Happy math.

PS. Here’s my cheatsheet full of “cartoonified” descriptions of math ideas.

## Other Posts In This Series

- Developing Your Intuition For Math
- Why Do We Learn Math?
- How to Develop a Mindset for Math
- Learning math? Think like a cartoonist.
- Math As Language: Understanding the Equals Sign
- Avoiding The Adjective Fallacy
- Finding Unity in the Math Wars
- Brevity Is Beautiful
- Learn Difficult Concepts with the ADEPT Method
- Intuition, Details and the Bow/Arrow Metaphor
- Learning To Learn: Intuition Isn't Optional
- Learning To Learn: Embrace Analogies
- Learning To Learn: Pencil, Then Ink
- Learning to Learn: Math Abstraction
- Learning Tip: Fix the Limiting Factor
- Honest and Realistic Guides for Learning
- Empathy-Driven Mathematics
- Studying a Course (Machine Learning) with the ADEPT Method

## Leave a Reply

52 Comments on "Learning math? Think like a cartoonist."

Khalid, could you better explain to me the concept of “i” being a 90 degree rotation? I would be really interested. I just love connections and concepts

Thanks

Diane

Definitely. Try checking out the article here, there’s some diagrams and a video as well:

http://betterexplained.com/articles/a-visual-intuitive-guide-to-imaginary-numbers/

In a nutshell, if we consider positive numbers to be forward, negative numbers to be backward, then imaginary numbers are sideways.

The main idea for imaginary numbers is that we don’t need to be stuck on the number line, we can take our numbers into 2d :).

“The main idea for imaginary numbers is that we don’t need to be stuck on the number line, we can take our numbers into 2d :).”

simple but deep. such sentences should be included in intro on imaginary number to affix the concept for-ever.

Enjoy your articles——–> keep them coming! Thanks.

Thanks Jeffrey, I appreciate it.

What’s funny is that all of these concepts are available in high school, where Euler should be taught in freshman year.

Hi Tim! I totally agree – the practical essence of Euler’s formula can be taught early on. Later, we can dive into the details (if needed).

Your articles are excellent! So useful for me as a maths teacher in Italy. I want my students to create cartoons on any concept I teach them – I’m sure it will help them remember as well as making it fun!

Thanks Dora, that’s a great idea. Trying to visualize ideas on your own is a good way to come up with new explanations, and one of your students might have a neat cartoon that helps the whole class!

Always a treat to see your insights !

Kalid, you’re the best!

Has someone ever asked you for permission to translate your articles to Portuguese? Sometimes I think about it. Could I do it with all the references? Actually, all your site, your book and your course deserve a full translation.

Kalid, please keep doing what you do, it’s amazing.

Neat summary!

@Pierre: Thank you!

@Frederico: Thank you! Yes, feel free to translate any articles you like and send me the link (or the text, and I can post them here). I’m keeping a list here: http://betterexplained.com/translations/

@John: Appreciate the encouragement, hope to keep going for a long, long time.

@Steve: Thanks!

[…] http://betterexplained.com/articles/math-cartoonist/ […]

Awesome. Are the Drawings yours?

@Mark: No, but I wish! They are from the blog post linked: http://www.tomrichmond.com/blog/2008/02/14/how-to-draw-caricatures-1-the-5-shapes/

Thanks for sharing this! We love the content and hope to keep seeing more great posts!

@notAprodigyInc

http://www.facebook.com/notAprodigy

Wonderful as usual. I try to get students to think of written math as pictograms, like Chinese writing. Sadly, I don’t reach everyone with this analogy but those that get it seem to love it.

Peter

@Peter: Thanks! Yep, not every analogy can work for everyone (no more than a food that everyone loves), but it’s at least a starting point. There might be other variations that people like if the first version didn’t click.

Thanks for this post!

I visit the site every once in a while during the year and find something interesting always; you seem to have a gift for teaching. :)

By the way, this is a little out-of-topic, but there’s a interesting course on Coursera called: “Learning How to Learn: Powerful mental tools to help you master tough subjects”, that started recently and seems to promote similar ideas to learn/understand more effectively complex topics, amongst other things.

hey brother will u please explane us about sequence and series, as welll as its relation with complex no., i mean both in real and complex part

Hey Khalid, I really like the way you teach and explain things. Can you please help me visualize dot product and cross product of vectors?

@Roberto, thanks for the pointer! I’ve just gotten in touch with Prof. Oakley, who is running the course ;).

@abhisek: I’d like to cover this topic too, thanks for the suggestion!

@Yash, I have an article on the dot product here: http://betterexplained.com/articles/vector-calculus-understanding-the-dot-product/

I don’t have one on the cross product yet, but would like to cover it down the line.

I teach statistics grad students to communicate and collaborate with non-statisticians. One module in my class is explaining statistics terms to non-statisticians. I make a big effort to distinguish an “explanation” from a “definition” and I give examples, but many of my students still “explain” terms via a definition. Ironically, I don’t think I explain “explanations” well enough, i.e., I can’t think of any analogies or diagrams to differentiate the two, just examples and technical differences. Do you have any tips for explaining the difference between an explanation and a definition?

I am so glad that I came across this site. I think this is the place that would be for my 4 year old. So glad that he and me will learn together mathematics :-)