blackpenredpen: calculus with two pens
Math teacher Steve Chow works through integrals and tricky problems on a whiteboard, switching between his trademark black and red pens.
What it is
@blackpenredpen is the TikTok account of Steve Chow, the math teacher many people know from his YouTube channel of the same name. His signature move is holding two pens at once: black for the working, red for the part that matters. The profile has more than 800 videos and close to 220,000 followers.
Why we picked it
Math on TikTok often means number tricks and viral "only geniuses can solve this" posts. This is different. Steve does actual calculus: integrals, derivatives, partial derivatives, limits. He taught at Los Angeles Pierce College for years, and it shows. Every step gets written out and said aloud, and the red pen lands exactly where students usually slip up.
There's also real enthusiasm. He loves problems with a twist and answers that come out unexpectedly clean, and watching a long messy expression collapse into something simple is oddly satisfying. The short format suits math surprisingly well: one idea, one video.
Where to start
- Open any integral video. That's his home turf.
- If you're taking calculus, search his profile for whatever your class is covering, from partial derivatives to limits.
- Pause before he reveals the answer and try the problem yourself. The videos are built for it.
- For longer walk-throughs, head to his YouTube channel under the same name.
Who it's for
College and high school students working through calculus. Teachers looking for good problems to steal. And adults who once enjoyed math and want that feeling back for a minute or two a day.
Quick answers
Who is behind it? Steve Chow, a math teacher and the creator of the blackpenredpen YouTube channel.
What level is it? Mostly college calculus, with some easier puzzles mixed in.
Where does the name come from? He writes with a black pen and a red pen, switching between them mid-solution.
