Thursday, December 27, 2012

More interesting snowflakes

Looking for something to entertain semi-distracted minds after the break?  How about challenging your students to fold paper and cut out a seven-sided snowflake decoration? 
Of course you could differentiate the task by starting off easier with 4- or 8-sided forms, increasing the challenge with more realistic 6-sided snowflakes, and asking particular students to bust out a 5- or 7- or 9- or 10-sided model.  Keep a chart on the board with the number of folds required and see what patterns your class can uncover. 
Here are my window decorations -

Sunday, December 16, 2012

MoMath Opening

Check out this video about the new Museum of Math in Manhattan, which opened yesterday.

Incidentally, the video is by George Hart, whose daughter Vi makes some sweet math videos of her own.

Thursday, December 13, 2012


This is an older one, but I wanted to take it out for another spin - here's my model of the old Spirograph toy. Nothing but the beauty of trig functions. [Fullscreen/Download]

(Sorry if you don't have Flash.) 

Friday, December 7, 2012

Library of Babel

Jorge Luis Borges' short story Library of Babel conceives of a library comprised of all possible books.  Specifically, all possible permutations of 25 characters (22 letters, comma, period, space) within books with 410 pages.  (Each page has 40 lines; each line has 80 characters).  This set of books would contain all books written so far (spanning multiple volumes if needed), along with all books that could possibly be written in the future.  The majority of the books in the library would be gibberish, of course.

A few questions, ordered from easy to hard:

  • How many books are in The Library of Babel?

  • How much space would this set of books consume (let's ignore the rooms and shelves, and just stack the books, which measure, say, 6 in. x 4 in. x 1.5 in. )?

  • What proportion of the books would read coherently from start to finish?

In this library, there would be a book explaining the solutions to each of these questions!