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.)

See all of our Math Monday columns

Gareth Branwyn

Gareth Branwyn

Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. And he has a new best-of writing collection and “lazy person’s memoir,” called Borg Like Me.

  • miroslava von schlochbaum

    no Ulam spirals?

    …still some nice patterns for clothing nonetheless.

    • Glen Whitney

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