MITx: 6.SFMx: Street-Fighting Math

School: MITx
Course Code: 6.SFMx
Classes Start: 8 Apr 2014
Course Length: 7 weeks
Estimated effort: 6 to 9 hours/week


algebra, trigonometry, and some knowledge of single-variable calculus

6.SFMx - Street Fighting Math

Street-Fighting Math

Teaches, as the antidote to rigor mortis, the art of educated guessing and opportunistic problem solving.

About this Course

Too much mathematical rigor teaches rigor mortis: the fear of making an unjustified leap even when it lands on a correct result. Instead of paralysis, have courage: Shoot first and ask questions later. Although unwise as public policy, it is a valuable problem-solving philosophy and the theme of this course: how to guess answers without a proof or an exact calculation, in order to develop insight.

You will learn this skill by mastering six reasoning tools---dimensional analysis, easy cases, lumping, pictorial reasoning, taking out the big part, and analogy. The applications will include mental calculation, estimating population growth rates, understanding drag without differential equations, singing musical intervals to estimate logarithms, approximating integrals, summing infinite series, and turning differential equations into algebra.

Your learning will be supported by regular readings that you discuss with other students, by short tablet videos, by quick problems to help you check your understanding, by weekly homework problems, review and and a final exam. You will work hard, and, by the end of the course, have learned a rough-and-ready approach to using mathematics to understand the world.

All required readings are available within the courseware, courtesy of The MIT Press. A print version of the course textbook, Street-Fighting Math, is also available for purchase. The MIT Press is offering enrolled students a special 30% discount on books ordered directly through the publisher’s website. To take advantage of this offer, please use promotion code SFM30 at The MIT Press. 

Ways to take this edX course:

Simply Audit this Course

Audit this course for free and have complete access to all of the course material, tests, and the online discussion forum. You decide what and how much you want to do.


Try for a Certificate

Looking to test your mettle? Participate in all of the course's activities and abide by the edX Honor Code. If your work is satisfactory, you'll receive a personalized certificate to showcase your achievement.

Course Staff

  • Sanjoy Mahajan

    Sanjoy Mahajan

    Sanjoy Mahajan is Visiting Associate Professor of Electrical Engineering at MIT, and Associate Professor of Applied Science and Engineering at Olin College of Engineering. In former lives, he was a faculty member in the Physics Department at the University of Cambridge, a Fellow of Corpus Christi College, Cambridge, and Associate Director of the Teaching and Learning Laboratory at MIT. He helped found the African Institute for Mathematical Sciences (AIMS) in Cape Town, where he was the first Curriculum Director and taught the first courses in physics and computer science.

  • Isaac Chuang

    Isaac Chuang

    Isaac Chuang is a professor of Physics and a professor of Electrical Engineering and Computer Science at MIT. His research focuses on quantum information and quantum computation. Professor Chuang leads the NSF IGERT on Interdisciplinary Quantum Information Science and Engineering at MIT. He is deeply involved in developing new methods for teaching and learning, as the associate director of MIT's Office of Digital Learning, and as a core developer of the edX platform.


algebra, trigonometry, and some knowledge of single-variable calculus


Do I need to buy a textbook?

Back in 2010, MIT Press agreed to publish the textbook, *Street-Fighting Mathematics*, under a free license (in print and online). Thus, the book is legally available all over the internet, including on this course platform. As a registered student in this course, you can also purchase a printed book from MIT Press at a discount.

Do you often get into street fights?

The last time was in high school, when I was attacked for being “different” and suspended for fighting back. However, in my problem-solving fights (and now that I’m older!), I regularly use reasoning tools and we’ll do the same in this course.