"I didn't understand the math, so the teacher…

A math joke was posted on the website Pun of the Day on March 18, 2012:

“I didn’t understand the math, so the teacher summed it up for me.”

Pun of the Day (March 19, 2012)
I didn’t understand the math, so the teacher summed it up for me.
R.A.D. - miami, FL

Twitter
MASTERMIND‏
@crazy_creed
I didn’t understand the math, so the teacher summed it up for me.[Click to Vote!]
2:05 AM - 19 Mar 2012

Jordan Ideas
Monday, April 15, 2013
Mathmaticious
(...)
First off, here are some math puns from punoftheday.com:
1. Some mathematicians are reluctant to cosine a loan.
2. I was kicked out of math class for one too many infractions.
3. A mathematician that couldn’t stop adding up recently went incremental.
4. I used to hate maths but then I realised decimals have a point.
5. I didn’t understand the math, so the teacher summed it up for me.

Acknowledging Anonymous
Monday, 28 December 2015
I didnt understand maths so the teacher summed it up for me.

Google Groups: The Grif.net
01/08/16 Grif.Net - Love Math?
Dr. Bob
1/8/16
(...)
I didn’t understand the math, so the teacher summed it up for me.

wattpad
April 23, 2016
Math Puns
by _spaced_out_
(...)
I didn’t understand the math, so the teacher summed it up for me.

Google Books
Masters of Mathematics:
The Problems They Solved, Why These Are Important, and What You Should Know about Them
By Robert A. Nowlan
Boston, MA: Sense Publishers
2017
Pg. 284:
I didn’t understand the math, so the teacher summed it up for me.

Twitter
RAMENCHAN3‏
@ChanelPonce
“I didn’t understand the math, so the teacher summed it up for me.”
11:36 PM - 7 Dec 2017

“I didn’t understand the math, so the teacher summed it up for me”