Pat Ashforth and Steve Plummer are two mathekniticians – maths people who not only knit and crochet, but present mathematical ideas through their yarn craft. And it’s fascinating!
They make afghans, wall hangings, tabletops(!), cushions, shawls, toilet-roll covers, puppets, sweaters, hats and so much more. Some of my favorites include these pillows and puzzles, for example…
…and the square root afghan:
Note: I wasn’t paid or perked to mention this; just passing along a good thing.