# Math Monday: Prime Wardrobe

By Glen Whitney for the Museum of Mathematics

Although Math Mondays has featured mathematical clothing before, it turns out there is an entire subgenre of clothing and accessories featuring those indivisible nuggets of the arithmetical world, the prime numbers. These range from the most basic, a list of prime numbers on the front (and composites on the back!) by “Longtalker” on Zazzle:

to an elegantly simple grid colored yellow or black depending on whether or not the corresponding number is prime, by EllieTs on CafePress

to this lovely hand-knitted sweater by Sondra Eklund which not only highlights the primes but in fact encodes the prime factorization of every number up to 100:

And here’s a variation on Sondra’s idea, a t-shirt using pie charts to encode the same information, by John Graham-Cumming:

Note the different order in which the numbers are presented by Sondra and John: one in “coordinate grid” order, and the other in “matrix entries” order. Finally, to wrap up this week’s collection, a linear presentation of the prime factorizations: a scarf which Sondra Eklund is (at least as of 2012 May 18, according to her blog) currently knitting.

(Thanks to the folks at Math Munch for the lead on today’s mathematical haberdashery.)

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### BY Gareth Branwyn

Gareth Branwyn is a freelancer writer and the former Editorial Director of Maker Media. He is the author or editor of a dozen books on technology, DIY, and geek culture, including the first book about the web (Mosaic Quick Tour) and the Absolute Beginner’s Guide to Building Robots. He is currently working on a best-of collection of his writing, called Borg Like Me.

### 2 Responses to Math Monday: Prime Wardrobe

1. miroslava von schlochbaum on said:

no Ulam spirals? http://en.wikipedia.org/wiki/Ulam_spiral

…still some nice patterns for clothing nonetheless.

• Well, maybe the world could use yet another piece of primewear…