Sara Jensen is an unusual math professor. Instead of calculators and textbooks, Jensen is teaching math with knitting needles and wool.

The Assistant Professor of Mathematics at Carthage College is on a mission to get people to re-imagine math, not as an abstract school of thought but as a method of better understanding the world around us. One way they do this is by teaching a math class where knitting and observation are the main tools.

## Professor uses knitting to teach math principles

In an entertaining blog post, Assistant Professor of Mathematics Jensen describes her unusual math classes and the results of this type of learning. She begins by recalling asking a group of college students what words came to mind when they considered mathmatics.

'“Calculation” and “equation” came out on top. When the same question was posed to professional mathematicians, the top responses were “critical thinking” and “problem-solving.”'

"When so many describe mathematics as synonymous with calculation, it’s no wonder we hear “I hate math” so often."

She explains, 'What professional mathematicians think of as mathematics is entirely different from what the general population thinks of as mathematics. When so many describe mathematics as synonymous with calculation, it’s no wonder we hear “I hate math” so often.'

'The Mathematics of Knitting' class begins by students knitting throw cushions that demonstrates a key aspect of mathematics, equivalence. Jensen explains that ‘fundamental to math is the equation, and crucial to this is the equal sign’.

She gives the example of x = 5. Mathematically x has the same value as 5. That is the number 5 and the value of x must be exactly the same.

Jensen says that in life things aren’t always so clear and that often ‘two quantities are not exactly the same, but are essentially the same by some meaningful criteria.’ To demonstrate this, students in her class knitted throw pillows from patterns that they made that they could then use to physically demonstrate the equivalence by moving the pillows.

## Rubber sheet geometry described with a wooly hat

Another important topic cleverly taught through craft is rubber sheet geometry. This field of thinking asks us to imagine the whole world being made of sheets of rubber and then reconceive what that means for shapes and topography.

If that seems confusing then think it through with a knitting example. One way to make round objects like gloves or socks is with knitting needles called double pointed needles.

The hat is made using three pointed needles that make the object being formed look like a triangle, however, when complete and slipped off the needles, the hat or glove softens and forms a circle. Rubber sheet geometry proposes that a triangle and a circle can be the same if they’re made out of a flexible material.

In this field of study, all polygons become circles. Students in 'The Mathematics of Knitting' class spent time knitting infinity scarves and other round objects to play with this theory.

Jensen says that by using conventional teaching tools she can open up the world of mathematics to a broader audience and help them embrace mathematical thought in their everyday life.