Street-fighting math from MIT

by rrusczyk, Feb 26, 2010, 6:50 PM

Among MIT's Open Courseware is some street-fighting mathematics, which consists of quick-and-dirty ways to avoid errors, make reasonable guesses, and find clever solutions. One excerpt I particularly like is this:

Quote:
Here’s what friends who went to the US Math Olympiad training session told me they were taught: Find the answer by any cheap method that you can find; once you know, or are reasonably sure of the answer, you often can then find a more elegant method and never mention the original cheap methods.

I think this is something a lot of people don't appreciate -- the top problem solvers are not necessarily the people who are best at finding the beautiful approaches quickly. They're often the people who can find any approach that works, which they may (or may not) then refine into the beautiful approach with more thinking. This is also one of the things I like about good math contest problems. The typical textbook problem is written with one solution method in mind. A good contest problem often has lots of successful approaches, and the interrelations between them can be illuminating, as well.

This is also a reason that our materials focus on the sausage getting made (the thought process we go through to find a solution) rather than the prepared meal (a polished solution) -- the latter is not nearly as illuminating, or as important, to the student who is trying to learn not the just the results, but how to produce results of their own.

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I used extreme-case analysis to get myself three quick points on the Fnet=MA contest, heh.

by CA Math, Feb 26, 2010, 8:23 PM

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Yeah, I know the author of that book pretty well. Lots of good stuff in there, though generally more applicable for physicists and engineers than for math olympiad-style problem solvers.

by joshuazucker, Feb 26, 2010, 11:59 PM

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Great class. It's a pretty short, Pass/D/F class over our IAP period.

He also teaches a full class during the semester along similar lines: The Art of Approximation in Science and Engineering.

by joml88, Mar 2, 2010, 4:49 PM

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Missed this post when it was first posted... but this sounds exactly like how I approach problems. Then again, one of my biggest weaknesses on contests is stopping the search for a better solution too soon, and therefore spending way too much on writing it up.

This is also a reason that it's a terrible idea to look at the solution to a problem without having made a ton of effort to solve the problem yourself.

by MellowMelon, Mar 19, 2010, 5:23 AM

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