Yes. I'm a math professor and I use a printer, although not too often. Most common use cases: - When I'm teaching, if I have typed up notes I'll print out a co

Yes. I'm a math professor and I use a printer, although not too often. Most common use cases: - When I'm teaching, if I have typed up notes I'll print out a copy to refer to in class. I can easily circle mistakes during class (to be corrected later), and I don't have to worry if I get chalk all over them. - For the reason that GlanFabien said. If I want to read a paper carefully (this includes a draft of my own work), I'll often print it out. This lets me scribble notes in the margin, take it with me easily, and it puts distractions one step further away. Conversely, if I just want to skim a paper I will just read it on a computer or tablet. - If I'm traveling I will print out copies of airline and hotel reservations and things like this. These aren't really necessary, I'm mostly just hedging my bets in case something goes wrong. Conversely, most things I don't print. For example I just read 250+ job applications, each of which comes with eight documents at a minimum (CV, statement of research plans, rec letters, etc.) and I printed none of them.