“What’s a math teacher’s favorite drink?”/“Root beer.”

A math riddle is:
 
Q: What’s a math teacher’s favorite drink?
A: Root beer.
 
The joke has been cited in print since at least 2016.
 
“If you put root beer in a square cup, does it become beer?” is another math and root beer joke.
         
 
Twitter
Andrew Wall‏
@Awall1894
What’s a math majors favorite drink? Root beer in a square glass 😂😂😂😂😂 #MathJokesForDays
10:27 AM - 9 Sep 2014
 
The Busted Knuckle Chronicles
Friday, 26 February 2016 00:00
Short chuckles
(...)
Q: What’s a math teacher’s favorite drink?
A: Root Beer
 
Twitter
notbannedbysoda‏
@n0tbannedbysoda
@Idubbbz @NFKRZAlt @HillaryClinton @realDonaldTrump @AmericanCancer What’s a math teacher’s favorite drink? ROOT BEER
7:38 PM - 25 Jul 2016
 
Reddit—Jokes
whats a math teachers favorite soda
submitted May 15, 2017 by Nanopois0n
root beer