MIT Course Number Mnemonics

When I first realized it might be helpful to start trying to remember the correspondence between MIT courses and their numbers, I expected a list of mnemonics for this correspondence would be one of those Things That Should Exist On the Internet. I’m pretty surprised it doesn’t. I mean, MIT has, what, at least 100,000 alumni; as far as I know, nearly everybody who goes there speaks the number correspondence fluently, so they have to learn it; and the science of mnemonics has been with us since the ancient Greeks and people who understand its usefulness can’t be uncommon, especially not in such a prestigious institute of higher education.

What gives?

I’m not sure. Maybe it’s just that nobody has posted their mnemonic set on the Internet out of embarrassment? My mnemonics are pretty bad too, but hey, Cunningham’s Law — if you’re reading, feel free to add better ones in the comments, or to criticize my horribly unenlightened and stereotypical characterizations of your courses, to make this thing better. Or maybe it’s out of concern that nobody else will find it useful? I get that feeling but my streak compels me to ignore it now, as it has for the last dozen posts or so. Or maybe they just didn’t optimize for search engine findability, so I can’t find it? I hope this post fixes that.

Actually, I guess the most likely reason is that maybe most people don’t actually have all the course numbers memorized with perfect recall, only the handful of most common ones they and their friends are in, and it’s perfectly fine to ask for clarification when an unknown number comes up in conversation, so nobody ever feels like they need to bother with mnemonics for every single course. Feels sensible to me.

But anyway, I’m not most people.

The most comprehensive resource of courses and numbers, including their history, appears to have once been at Many, many links point there. Unfortunately, it is dead and I cannot find its new home, if it has one. Fortunately, there is an archived version on; on the other hand, I am not sure whether any updates have occurred since it was archived. A more recent version with course populations from 2005 is this chart linked from the MIT Admissions blog post Numbers are names too.

Speaking of which, I realize that this chart will likely reduce the effectiveness of using course numbers as a shibboleth, which the blog post appreciated. But I say if this mnemonic set can reduce the cognitive load of a few other MIT students, so they have more time and more energy to spend on academics and self-actualization and various important things, then it’s worth it. (I don’t care either way. I have fun memorizing weird things.)

Anyway. This is a pointlessly long introduction, isn’t it? One final note: my mnemonics only go over the unembellished numbers. I don’t list mnemonics for remembering sub-courses with number or letter suffixes, including the humanities courses that start with 21, or the letter abbreviations, because (1) I think they’re easy enough to remember without a mnemonic and (2) I’m on a schedule and I can always add those later if anybody cares.

  • 1, Civil and Environmental Engineering:

    As environmentalists like to say, we’ve got one earth. Let’s not screw it up, please.

    A strict majority of the letters in the word “civil” can be mistaken for 1 in sans-serif fonts. That’s gotta count for something.
  • 2, Mechanical Engineering:

    This… looks like a hook, which is something you can use to like pull stuff as an engineer.

    Alternately, this field of study is what makes the machines that get you from somewhere 2 somewhere else.
  • 3, Materials Science and Engineering:

    3 is fluffy! :3 You want engineers to fluffy materials to make fluffy chairs to sit on! That’s pretty bad.

    Okay, there’s a song:

    ‘Cause we are living in a material world
    And I am a material girl~

    What’s the relation to 3? I think “third” can kind-of-sort-of rhyme with “world” and “girl”, if you slur your words enough. At least I think it comes closer than any other number or derivative word.

    Also, looking at the history of this course, it was first Mining and then Metallurgy before becoming Materials. The conspicuous feature all three(!) of these words have in common is starting with the letter M, which becomes a 3 if you tilt your head sideways.
  • 4, Architecture:

    Squares and rectangles have four sides and are the most common shapes of buildings and windows and stuff.

    “Four” sounds like “fort”. To prevent yourself from thinking “force” instead, note that “fort” also has four letters and is a prefix of the course 14 mnemonic, “fortune”. Read on.
  • 5, Chemistry:

    “High five” and “chemistry” are both colloquially used in contexts describing people who get along well.

    Element number 5, Boron, is the first element to have the same number of letters in its name as its atomic number. It also has the alphabetically earliest symbol with 1 letter.

    There are several lists of classical five elements, maybe most notably the Wu Xing (I didn’t know it was called that until I looked it up), 金木水火土 = metal, wood, water, fire, earth, in the order I usually hear the Chinese characters in. (Although unfortunately, but understandably, there are other lists of classical elements you have to ignore, including the four Aristotelian elements and seven chakras. Still, five is the median.)
  • 6, Electrical Engineering and Computer Science:

    6 rhymes with UNIX. And the alluringly assonant “bit shift tricks”. And sticks, which may be considered an extremely primitive method of counting that evolved into computers?

    If you write the letters C and S on seven-segment displays (certainly something one would expect to see in EECS courses, right?) and superimpose them, you get 6. You can include the Es too. Here it is in sketchy Unicode box-drawing characters:

    ┌─╴ ┌─╴ ┌─╴ ┌─╴ ┌─╴
    ├─╴+├─╴+│  +└─┐=├─┐
    └─╴ └─╴ └─╴ ╶─┘ └─┘
  • 7, Biology:

    Umm, biology has seven letters.

    Often, there are seven taxonomic ranks, starting with Kingdom and ending with Species (as in, King Philip Came Over From Great Spain). You have to omit “Domain” for this to work though.

    Evolution is a major part of biology and is all about survival of the fittest, which means elimination of the weak, and there are seven days in a week.

    Wikipedia says that “almost all mammals have 7 cervical vertebrae”. But I’m guessing that unless you’re already seriously considering this major and are thus really familiar with its number, you didn’t know that. I sure didn’t.
  • 8, Physics:

    The figure 8 looks like… two planets orbiting each other. The result of a nonelastic collision. Eyeglasses, as in the sort of thing involved in optics problems in physics.
  • 9, Brain and Cognitive Sciences:

    If you squint really hard, 9 is probably the number that looks the most like a thought bubble.

    edit: phenomist points out that 9 also looks like a brain with the brainstem.
  • 10, Chemical Engineering:

    10 is twice 5. This is the chemistry-involved major with twice as many words in its name as its pure relative, Course 5.

    I guess Chemical X (Roman numeral for ten) is an example of chemical engineering instead of pure chemistry?
  • 11, Urban Studies and Planning:

    It’s like 7-11s, and 7 is taken, so just imagine some person marking up the optimal positions of 7-11s in a city even though I’m pretty sure urban planning has nothing to do with that. (I realize that 7-11s are abnormally common in Taiwan, so this mnemonic may be much harder for others to associate than for me. Suggestions are welcome.)
  • 12, Earth, Atmospheric and Planetary Sciences:

    Twelve sounds like elves and elves live in Middle-Earth. This is pretty bad.

    Why are there twelve months in a year? Why is the lunar cycle about one-twelfth of the solar cycle? Planets and stuff.
  • 13: This doesn’t exist because it’s unlucky. But it used to be Ocean Engineering. If you want to remember that, maybe link 13 with superstitions like hell or the devil and note that the ocean is probably physically closest to that region.
  • 14, Economics:

    “Fourteen” sounds kind of like “fortune” which is what you can make if you go into economics, maybe. Or at least you get to study stuff including other people making them.
  • 15, Management:

    Kirkman’s schoolgirl problem classically involves 15 people. That’s about managing interpersonal relations, right?

    Also I heard there’s an influential book called Mythical Man-Month. There are 30 or 31 days in most months but course numbers don’t go up to 30 so just halve that and you get 15.

    Okay, fine, this is the very first thing that pops into my head when I think of the number 15 and I have to force this in somehow:

    Cause when you’re fifteen
    and somebody tells you they love you
    you’re gonna believe them
    Even if the two of you work at the same shady dead-end job
    And if you break up soon tell me who can purge the workplace of your awkwardness?
    Which course can figure out this corporate mess?
    I am reasonably confident this is a worse misrepresentation of the course than my 11 mnemonic. I’m sorry.
  • 16, Aeronautics and Astronautics:

    The number looks like a telescope pointing straight up and a comet with a tail going through the sky. You need the telescope since comets flying out there by themselves don’t automatically create human inquiry.

    “Aeronautics” and “Astronautics” both have 4 syllables, so you multiply them together (don’t ask why) and you get 16.
  • 17, Political Science:

    As everybody knows[citation needed], this is the most random number and, compared to all these physical processes and laws of nature, what could be more random than the macroscopic behavior of people and their votes and opinions? Really. Eh, I don’t know.
  • 18, Mathematics:

    Eighteen loosely rhymes with rating so imagine some dude developing a formula for rating systems.

    I would really like to make something out of viewing this sideways and seeing something involving infinity, but I can’t make it work and I’m not really motivated to come up with a better mnemonic, since this is my most likely major and I think I’ll remember it.
  • 19: This doesn’t exist because Miss Zarves. Apparently it used to be Food Sciences — as in, “food for thought”, and 9 is a thought bubble, so just imagine that the 1 is a cheese stick or celery stalk or Pocky or something — and now unofficially refers to roof and tunnel hacking (from this everything2 post).
  • 20, Biological Engineering: Presumably this is the field that eventually hacks our brains and optic nerves to give us all 20/20 vision.
  • 21, various humanities:

    21 is the U.S. legal age for drinking and I have no idea but maybe you can convince yourself that some people get inspired and become a lot better at certain aspects art or writing or whatever when drunk, which doesn’t seem to me to apply so readily to any of the other subjects here.

    The six courses that start with 21 are:

    • 21A, Anthropology
    • 21F, Global (F for Foreign) Studies and Languages
    • 21H, History
    • 21L, Literature
    • 21M, Music and Theater Arts
    • 21W, Writing
  • 22, Nuclear Science and Engineering:

    There is a phrase “to put two and two together” which comes to mind and which can be linked to nuclear fusion; just imagine two nucleons and two nucleons smashing together.

    Alternately (of course (I’m really sorry)) from a prospective major examining the field: “I don’t know about you U238 / But I’m feeling 22”
  • 23: This doesn’t exist because the 23rd letter of the alphabet has a really weird number of syllables. The archived site says it used to be Modern Languages, and then Foreign Literature & Linguistics. Yeah, the weird number of syllables in the letter W is totally the reason why people feel driven to study other languages where the rules are a little more sane. (phenomist adds that you can also consider loanwords in English that use w as a vowel.) Step up your game, English!
  • 24, Linguistics and Philosophy:

    If you flip 24 around you get 42, the well-known answer to life, the universe, and everything. The way the digits are flipped is a reminder that philosophy is the second subject in the name.
  • If you still care, 25 used to be Interdisciplinary Science. 25 is 5 times 5 and 5 looks like S so it’s like multiplying Science and Science, or the 25th letter is Y and figuratively represents two sciences coming from the top and merging into one at the bottom.

For completeness, here are the three-letter courses. Unless you enjoyed the above mnemonics so much that you’d buy me a drink or something to twist out mnemonics from these letter triplets, you’re on your own for memorizing these.

  • CMS: Comparative Media Studies (MIT’s courses page slashes this with 21W, Writing; I don’t know what that means)
  • CSB: Computational and Systems Biology
  • ESD: Engineering Systems Division
  • HST: Health Sciences and Technology
  • MAS: Media Arts and Sciences
  • STS: Science, Technlogy, and Society
  • WGS: Women’s and Gender Studies

For complete completeness, the archive page lists these (presumably) defunct ones, which you probably don’t care about:

  • PG: Fuel Gas Engineering
  • GP: Group Psychology
  • HPM: Health Policy & Management
  • TOX: Toxicology
  • TPP: Technology & Policy Program

Congratulations! You’re done memorizing the course numbers of one of the most notoriously intense colleges in the world. You may now commence trying to memorize the actual content of those courses so you can get your degree. (Please remember to try understanding that content as you go along.) You can test your knowledge with this Sporcle quiz (slightly funky in that it’ll confirm your answer as correct once you type in one word for many of the numbers and abbreviations, especially in the beginning, but not all of them) or this Quizlet set.

(note: the commenting setup here is experimental and I may not check my comments often; if you want to tell me something instead of the world, email me!)