Image 1: A computer running the web version of Desmos, and a phone running the Desmos mobile app. Photo by Daniel Havlat.
Eli Luberoff (YC ’09) is the founder of one of the most well-known online tools in math education: Desmos, the online graphing calculator used by over seventy-five million people annually.
Luberoff’s inspiration to create Desmos came from his exposure to math students who struggled to pay the high cost of physical graphing calculators. While at Yale, Luberoff tutored students in Westport and volunteered at New Haven public schools through the MathCounts Outreach program. Luberoff’s experiences opened his eyes to the financial burden of graphing calculators. “It’s completely unacceptable that every other part of the technology spectrum has come down so far in cost or gone up so far in performance, but [graphing calculators] have just been frozen in time for thirty years,” Luberoff said. Hoping to reduce disparities in access, Luberoff started to consider the possibilities of a web-based graphing calculator that was accessible, equitable, and convenient. He described the genesis of Desmos as an “accidental experiment” rather than a goal-focused approach. He had learned to code in the programming language C++ in middle school, and the rudimentary graphing calculator he created was at first just a passion project.
In seventh and eighth grade, Luberoff was homeschooled but went to UMass Amherst to take math, physics, and language courses. Two years later, he started going to Amherst College to take courses there, where he was able to study math at a much higher level than a high school curriculum. Luberoff noted how he was able to build relationships with college students and professors much earlier than normal. “Looking back, I realize that was just an absolutely absurd opportunity that I had that very few people have,” Luberoff said. “And so a lot of that motivated the work to say, ‘How can we make public education better?’”
After Yale, Luberoff started to build Desmos. One of the first obstacles was procuring funding from investors. “The goals that I’ve had have always been different enough from the goals of most investors. We never want to advertise. We never want to sell user data. We did get really lucky with some investors, but I think it was definitely challenging for a long time to get people to think that this opportunity was big enough,” he said. Luberoff found that educational conferences were more receptive to Desmos than technology-focused events, which didn’t focus on his mission of increasing educational accessibility.
After some time, Desmos started to take off. “I remember so distinctly the first time that I noticed that a couple hundred people used [Desmos] that day, and to me, that was completely unfathomable. And every year, I would look back and think, ‘that number was kind of small.’” Now, millions of people use the software on any given day, and for more than drawing pictures using equations, which was its initial appeal to users.
Desmos’s current business model runs on partnerships, which allows organizations and companies to integrate the calculator into a curriculum or a test. In fact, Desmos is now the official calculator for the SAT. When students open their test, they can press a button in the corner that pulls up a secure version of Desmos, allowing them to access their saved graphs. Desmos is also in “a number of the ACT exams” and forty-three out of the fifty state tests. “I’m very, very proud of [this]. I think the benefit is that kids can practice for free at home on the exact same thing they’re going to see on the test, so it’s a more fair and equitable test,” Luberoff said.
Luberoff and his team have also been working on creating new features in Desmos. Due to high demand, they have recently released a beta version of 3D graphing at https://www.desmos.com/3d. Luberoff said they also have someone on their team leading efforts to ensure that visually impaired and blind students can use Desmos. “For example, you can take a graph and play it as a sound to be able to hear the shape of the graph,” Luberoff said.
Luberoff describes these kinds of accessibility features as his favorite thing to demo at conferences because of how they pull the audience in. “Most software doesn’t consider people with these kinds of accessibility needs, and so when [a software] actually does, it’s so transformative,” Luberoff said. “Their stories always blow my mind, and those are the ones that just make it all worth it.”