“What do you call a math balled?”/“A musical number.”

A math riddle is:
     
Q: What do you call a math balled?
A: A musical number.
   
The joke was posted on Facebook by Zachary Dykeman on June 4, 2021.
   
     
Facebook
Zachary Dykeman asked a question .
June 4, 2021 at 5:23 PM ·
What do you call a Math Ballad?
Musical number
 
Twitter
Joe William Bowles II
@JoeWBowles
What do you call a Math Ballad?
A Musical number
5:27 PM · Jun 4, 2021·Twitter Web App
 
Twitter
mariana Z
@mariana057
What do you call a Math Ballad?
Musical number….
8:47 PM · Jun 7, 2021·Twitter for iPhone