Skip to Content
MIT News magazine


MIT has always been fond of enumeration

When freshman Yan Zhu flew from St. Louis back to Boston after winter break, she overheard two people bandying about seemingly random numbers a few rows in front of her seat. “Suddenly, I realized, ‘Wow, I know exactly what you’re talking about!’” she says–they were MIT students talking about classes. By then she was well versed in this unique number-speak. But even before she matriculated, she says, “I had heard about our numbering obsession through the Internet.” In fact, that “obsession”–MIT’s penchant for numbering classes, buildings, and “courses,” or majors–began when the Institute was just a fledgling school in the Back Bay.

The numbers brought to life: Part of a whimsical map of MIT drawn by geology professor Frederick K. Morris in 1944–’45.

In 1865, MIT offered six courses of study, each assigned a number: mechanical engineering (1), civil and topographical engineering (2), practical chemistry (3), geology and mining (4), building and architecture (5), and general science and literature (6). Over the years, course numbers have been added, deleted, or reassigned as the need arose. For example, when MIT separated the food technology program from the Department of Biology and Biological Engineering in 1945, the distinction was formalized a year later by assigning a new number, Course20. Food technology retained that numeric moniker as it morphed into nutrition and food science and, later, into applied biological sciences. When MIT discontinued the program in 1988, the number was retired for nearlytwo decades and then reassigned to biological engineering in 2006.

The practice of numbering buildings began when contractors Charles A. Stone and Edwin S. Webster, who had graduated from the Institute in 1888, drew up construction plans for the Cambridge campus that would be completed in 1916. Using numbers or letters for buildings was common among factories at the time, observes the MIT Museum’s science and technology curator, Deborah ­Douglas: “That’s part of industrialization–keeping track of numbers.” Stone and ­Webster identified each sector of the main building by number, assigning odd numbers to the left of the dome (as viewed from the Charles River) and even numbers to the right–a pattern that remains today on the main campus. (In fact, they numbered every piece of stone and equipment in each building.) The Institute embraced the idea from the start. “MIT anticipated the need for a numbering system,” says O. Robert Simha, MCP ‘57, a research affiliate in the Department of Urban Studies and Planning, who directed MIT’s planning office from 1960 to 2000. The practice of referring to spaces by building number followed by floor and room number was convenient and flexible; as buildings were added or interior spaces altered, the numbers could just be modified as needed.

In the 1940s, as MIT began to expand to West Campus, Don Whiston ‘32, MIT’s associate director of physical-plant operations, created a grid that established a numbering sequence for additional buildings, using Memorial Drive as a baseline. In the 1960s, when Simha developed a master plan for future construction, he extended the grid to the east, north, northeast, and northwest sectors. Doling out numbers for new buildings is quite systematic–but there’s some wiggle room. When the Stata Center was built where Building 20 once stood, it seemed sacrilegious to reuse the number, given Building 20’s iconic status. Instead, a committee of faculty and administrators recommended the number 32. “Computer scientists typically do everything in powers of two,” explains Professor John Guttag, who was then head of electrical engineering and computer science. They felt that their department’s new building number should be a power of two–and 32 had for years been the standard number of bits in a typical computing “word.” “It just seemed so right,” he recalls. “It seemed almost like destiny that 32 was sitting there unused.”


  • Download a PDF of the above map.

Although numbers clearly serve a practical purpose at the Institute, MIT students know how to have fun with them, too. For instance, when Building 7 opened in 1938, theTech reported that if the 8,500 cubic yards of cement used for the building were poured into 12-ounce beer cans, they would fill 18,250,000 of them–6,300 for each student. And on the night the movie Harry Potter and the Goblet of Fire was released in 2005, hackers turned Building 9 into Building 9¾ in honor of the train platform Harry uses to get to the Hogwarts School for Witchcraft and Wizardry. Students relabeled office doors, classrooms, bathrooms, and even the mail room.

Simha thinks MIT’s numbering culture reflects the value that people here place on logic and quantitative accuracy. And fluency in numberspeak is a matter of pride for students, he says. For Zhu, it’s just more efficient. “MIT students like to shorten things,” she says. And, she adds, it’s a way of identifying yourself as an MIT person wherever you are–even at 30,000 feet.

Keep Reading

Most Popular

This new data poisoning tool lets artists fight back against generative AI

The tool, called Nightshade, messes up training data in ways that could cause serious damage to image-generating AI models. 

Rogue superintelligence and merging with machines: Inside the mind of OpenAI’s chief scientist

An exclusive conversation with Ilya Sutskever on his fears for the future of AI and why they’ve made him change the focus of his life’s work.

Data analytics reveal real business value

Sophisticated analytics tools mine insights from data, optimizing operational processes across the enterprise.

Driving companywide efficiencies with AI

Advanced AI and ML capabilities revolutionize how administrative and operations tasks are done.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at with a list of newsletters you’d like to receive.