In the depths of Pornhub, buried beneath a mountain of hardcore erotica, a 34-year-old Taiwanese man named Changhsu (張旭) taps away at a green chalkboard while speaking a steady stream of Mandarin. In nearly all of his 226 videos, he wears a gray hoodie and black-rimmed glasses, and he never once does anything even remotely pornographic — no blow jobs, no 69s, no anal. He’s on Pornhub for a different reason: To teach calculus.
Changhsu has a master’s degree in mathematics, and he’s been teaching online and in Taiwanese cram schools — which provide supplementary learning classes for determined students — for 15 years. He lectures on YouTube, and in 2020, he developed an online course with its own dedicated URL. If his 520 positive Facebook reviews are to be believed, he’s a fantastic educator — most of them are some variation of, “Nice teacher!”
Last year, Changhsu saw an opportunity to spread his numeric gospel on Pornhub. “Since very few people teach math on adult video platforms, and since there are so many people who watch videos on them, I thought that if I uploaded my videos there, a lot of people would see them,” he tells me (Changhsu asked us to edit his English for clarity, because it’s not his first language). It’s true that non-pornographic videos like “I Deliver You a Pizza and Don’t Put My Weiner in It” or “Minecraft Tips and Tricks 3: Fast and Free House” aren’t uncommon on Pornhub, but Changhsu appears to be the only math teacher on the website (unless “Jerking off to CALCULUS” counts).
In fact, Changhsu even tried to extend his reign to other adult websites like XVideos and XNXX, but he says “those platforms know which kinds of videos are adult and which aren’t, and they forbid them.”
Still, Changhsu had success uploading to Pornhub under the name changhsumath666, and he was initially hoping that the peculiarity of teaching calculus on a porn site would work as a spectacle, spurring conversation and increasing his overall reach. “People may not be interested in my videos, but they’ll all know there’s a teacher who teaches calculus on an adult video platform,” he explains, adding that he suspects that 60 percent or more of his viewers come to his Pornhub channel for a laugh, rather than to learn calculus.
This makes sense, seeing as many of Changhsu’s videos run for as long as 50 minutes, and they feature (translated) technical titles like “Differential Application Chapter 4: Differential Extremum Method” and “The Focus of the Limit Chapter 4: Theorem of Limit Operations.” Nonetheless, you may feel inclined to click on one if it pops up while you’re browsing Pornhub, then the “Recommended” sidebar will thrust you straight back into actual porn once you grow tired of calculus.
So far, Changhsu’s plan to garner acclaim has worked well. He has 1.6 million video views on Pornhub and says it directs business to his more profitable online course. “Many students who need a teacher who can teach math know me through Pornhub, and some of them buy my course,” he says. Altogether, his online course pulls in 7,500,000 New Taiwan dollars (over $250,000 U.S.) per year, which he uses to pay his bills and provide a decent salary to his employees, who help him teach on his various platforms.
By and large, the Pornhub community has accepted Changhsu and his lessons. Not only is he a verified Pornhub member, but the comments beneath his videos are mostly wholesome and welcoming. For instance, a user by the name of Hanimechann says, “Thanks, I needed this for my math finals.” Another who goes by RobertsHoles writes, “This guy will do anything to reach his students!”
It’s comments like these that keep Changhsu going. “Reading them, I know there are people who know what my real plan is,” he tells me.
But there’s also the occasional comment that brings Changhsu down — e.g., a user known as EnemySpiderMoment types, “Uh, not what I expected to see while looking through Pornhub today.”
“I can still feel his or her negative emotion from that sentence,” Changhsu says.
No matter what happens on Pornhub, though, the platform is merely a means to an end for Changhsu, and he has bigger plans for his future. “I didn’t want to teach math on Pornhub,” he tells me. “I wanted to let the world know that I’m a teacher from Taiwan who can teach calculus well.”
Well, you know what they say: Nothing grabs people’s attention like a cream pi.