A blog about math, puzzles, teaching, and academic technology

Euler's Gem: The polyhedron formula and the birth of topology

Princeton University Press

2008

Euler's Gem Facebook page

Buy it:

Princeton University Press

Amazon

Princeton University Press

2008

Euler's Gem Facebook page

Buy it:

Princeton University Press

Amazon

- 355/113 is a good rational approximation for π and its "mirror" 553/311 is a good approximation of sqrt(π) (although 553/312 is better). 13 hours ago
- The first 0 of π is the 33rd digit. 14 hours ago
- Silver lining to sitting in O'Hare all day: My #MAAthFest talk is done. (Thurs., Aug. 4, 10:15, Union D room, in case you're interested.) 16 hours ago
- My wife, last week: You're flying through O'Hare? That'll be trouble. Me: It'll be fine. It isn't winter ... My wife (just now): Told you so 18 hours ago
- Roy Adler (1931-2016)—influential researcher in ergodic theory and dynamical systems bit.ly/2a69Quw 2 days ago

- How to curve an exam and assign grades
- What is the difference between a theorem, a lemma, and a corollary?
- Music is math: ten songs about mathematics
- LaTeX now available in Google Docs
- Make a Sugihara Circle/Square Optical Illusion Out of Paper
- Sugihara's Circle/Square Optical Illusion
- The importance of definitions: chance of rain
- Is or an inclusive or or an exclusive or?
- Cardinality of infinite sets, part 1: four nonstandard proofs of countability
- Look who majored in mathematics

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