“I use knitting to teach maths to my students”
Avid knitter, Sara Jensen, reveals why knitting is such a useful tool in the classroom, not least when it comes to teaching the magic of numbers!
Keeping handknitting alive in such a modern, technologically-advanced world seems more important than ever. Not only is knitting fun and useful, but there are many things it can be used for – for example, learning maths! We talked to Sara Jensen, Assistant Professor of Mathematics at Carthage College, Winconsin, USA, who uses knitting to teach her students – something she calls, ‘The Mathematics of Knitting’.
Sara started knitting at a young age, but stopped during her teens. “I started again in graduate school as a relief from doing mathematics all day,” she tells us, and soon started seeing mathematics within her knitting. “When I would try a new skill or pattern I would try to work out why this particular pattern would yield the result I wanted. I began to realise there was a lot more mathematics in knitting than I initially suspected.”
Sara decided to show her discovery to her students, as a means of helping them to understand maths. “Carthage College o ers a unique experience called J-term, where students take only one course all term. Professors are encouraged to o er unconventional classes during this time so I proposed The Mathematics of Knitting.” So, what would a typical ‘Mathematics of Knitting’ task be? “One of my favourite projects from The Mathematics of Knitting course was a lacework headband (www.ravelry. com/patterns/library/arrowhead-lace-headband),” Sara tells us. “We used the concept of lacework to describe mathematical functions. A function is just a process that transforms one set of things (an input) into another set of things (an output). In this way, the process of taking the knit stitches on the left-hand needle and transferring them to the right-hand needle is a function – the left-hand stitches are the input, the right-hand stitches are the output, and how you knit them is the function. I used the lacework headband to ask students to describe exactly how the stitches on the left-hand needle became the stitches on the right-hand needle. This is particularly interesting with lacework because sometimes two stitches ‘become’ one stitch (for example, with a k2tog) and sometimes a stitch comes from nowhere (with a yo).”
Sara learned the basic stitches as a child, when her grandmother taught her how to knit. Her favourite type of knitting is Fair Isle knitting. “When knitting Fair
Isle, I use the rule that no more than five consecutive stitches can be the same colour. This, along with the fact that you must knit Fair Isle in the round, puts a limit on the di erent patterns that can occur as Fair Isle patterns for a given row of knitting. This context of Fair Isle knitting gives students an introduction to a mathematical subspeciality called number theory, and in particular, can be used to introduce a special mathematical function called the partition function.”
Sara’s passion for knitting really shines through her unique teaching method, “What I love about knitting is the challenge it o ers and the sense of accomplishment you feel,” Sara explains. “This is almost exactly the same reason I love mathematics.”
To find out more about Sara’s mathematical teaching, visit www.sarajensen.org and www.carthage.edu/live/profiles/1174-sara-jensen-08