How Sidewalk Math Cultivates a Playful, Curious Attitude Towards Math

At first, the provenance of the math problems was a mystery. The chalky, pastel words, numbers and symbols appeared on sidewalks near a small park in San Diego not long after the COVID-19 shutdown began. Families taking walks paused to ponder the patterns. They discussed possible solutions. They took photos to share with others. Within a few days, teacher Traci Jackson, who lives a few blocks away, started receiving messages from friends and neighbors. “Is that you leaving math everywhere?” they asked. Jackson’s secret was out, but her public math mission wasn’t over.

Changing the environment of math changes how people respond to it, said Jackson. She first observed this shift a few years ago when, inspired by teacher and blogger Sara Van Der Werf, she posted a math problem in the hallway at her school in Poway Unified School District. Jackson watched with delight as not only students but colleagues and parents lingered by the problem, their curiosity piqued. Instead of feeling pressured to get the right answer quickly, passersby were willing to think about the problem for a bit or get it wrong and revise their thinking. Now, with schools closed, Jackson is replicating that magic by decorating her neighborhood with sidewalk math problems. 

Conscious of the “negative vibes” that often surround math, Jackson said she loves seeing people in her neighborhood and around the world experience the subject in a curious and playful way. One child in her neighborhood wrote code for drawing a square fractal based on one of the problems. Another neighbor shared the problems with her 83-year-old father-in-law, who has enjoyed the digital versions from afar. “I am glad she is not on my walking route. I might never get home,” he joked.

“The perception of math is a set of sterile problems but in reality it describes all the patterns of our world. … [Sidewalk math] opens the conversation to what math is. It engages people who wouldn’t do math ordinarily,” Jackson said. She believes that the visual element plays a role in that engagement. Stanford professor Jo Boaler has advocated for the learning benefits of visual math for years, but Jackson said it remains an under-explored dimension of math instruction. Though we often think of math as numbers and letters, Jackson sees it as a way of viewing the world, and using images can unlock new connections.

For her creations, Jackson uses problems from a range of resources collected over her years as an educator. Some focus on patterns, others cultivate number sense and some involve algebra. Sometimes the problems incorporate movement. Jackson aims to make sidewalk math accessible to a wide age range. For example, in a “Which One Doesn’t Belong” problem featuring the numbers 9, 16, 25 and 43, a younger child might notice that 9 is the only single-digit number while a teenager might recognize that all the numbers except 43 are perfect squares.

Though her tweets and blog have helped popularize sidewalk math during coronavirus, Jackson is not the first one to do it. In 2018 and 2019, Brian Palacios, a public school teacher in the Bronx, shared the idea at several teacher conferences in New York City and Boston. At some of those events, educators put the idea into practice immediately. Others brought it back to their schools to do with students. “It’s not going to change the world, but it could help move the needle a tad bit towards spreading math and including more people in conversations about math,” Palacios wrote in a blog post.

Jackson echoed that sentiment when discussing her pursuit. “I feel like I’m giving math, and that makes me happy,” she said. For others interested in creating sidewalk math in their neighborhoods, she recommended starting with problems others have used and then getting creative. With high demand for low-tech entertainment during coronavirus, the hardest part may be finding chalk.