This lovely mathy hat was inspired by the great Grumperina (http://grumperina.com/knitblog/) and her adventures in helical knitting (http://grumperina.com/knitblog/archives/2008/06/helical_s...), as well as by the gentle pestering of my mathematically-inclined friend and co-worker, Spencer, for whom it was created.

Three rows of ribbing, three colors of continuously spiraling helical striping, six-part decreasing in order to create diminishing hexagons in the spiral as it works its way up? This thing is practically an episode of Schoolhouse Rock. Three is a magic number, indeed.

This original hat was made to fit heads up to 24”, and changes in size can be made easily by decreasing/increasing the number of stitches cast on in multiples of six.