Skip to main content
The equation of choice among math paradoxers and recreational mathematicians, who unspokenly derive much satisfaction in exposing students’ fallacious or illogical reasoning that leads to the contradictory result.
Be it due to division by zero or squaring (or square rooting) both sides of an equation, few students wouldn’t want to know why “1 = 2” is logically plausible.
1 = 2 by Fasters May 3, 2022
Urban Dictionary Merch
Your favorite words on things you can wear, drink from, read, or give to a friend.
The Urban Dictionary Store sells gifts you’ll have to explain.
The person before made a mistake in their proof.
1. x = y
2. xy = y^2
3. xy - x^2 = y^2 - x^2
4. x(y - x) = (y + x)(y - x)
So far so good.
4.5. x = (y + x)(y - x)/(y - x)] is what they did to get to step 5, which says:
5. x = y + x

This is wrong though. since x = y, y -x = 0, and so you can't divide by y - x.
Anyone who says 1 = 2 is wrong.

1 != 2
1 = 2 by mathisfun March 17, 2008
1. x = y
2. xy = y^2
3. xy - x^2 = y^2 - x^2
4. x(y - x) = (y + x)(y - x)
5. x = y + x
6. x = x + x
7. x = 2x
8. 1 = 2

QED
As proven, 1 = 2, thus 0 = 1, etc. And so for any number i, there is an equivalent j that is not equal to i.

This is further explained in the Identity Theft Theorem.
1 = 2 by SAH aka the GSH October 17, 2006

1 + 1 = 2 

It has taken years for scientists to do all the studies to thus prove that 1 + 1 is actually 2. After a long and hard (lol, long and hard) test involving one apple, than adding another. The tests were proven that 1 + 1 is in fact, 2.
White boy: Omg, this is so hard, could you help me with my math?

white boy 2: Errr, the answer to that question is. 1 + 1 = 2.
1 + 1 = 2 by Anti Bit February 4, 2009

1 + 1 = 2 

When a math is close to, if not OBVIOUSLY easy

or you just don't want to help the person finding the answer
Person 1: Arrgh! i just cant get this right, could you please help me?

Person 2: Yeah, 1 + 1 = 2
1 + 1 = 2 by TheLittleMe October 4, 2011

3 + 2 = 1 

A mathematical statement most grades K–2 students would disqualify as being an equation, thus revealing their partial understanding of the meaning of an equals sign, which has different meanings.
What percentage of elementary math students (and their teachers and parents) would claim that statements like 1 + 3 = 2, 3 + 2 = 1, and 2 × 3 = 1 aren’t equations, because the sum or product is incorrect?
3 + 2 = 1 by Fasters May 9, 2022

1 + 2 + 3 = 1 × 2 × 3 

The nontrivial solution to the equation a + b + c = a × b × c, where a, b, and c are positive integers—the sum and the product of three whole numbers are the same.
Besides 1 + 2 + 3 = 1 × 2 × 3, the numbers 1, 2, and 3 form the set of three integers such that each divides the sum of the other two, and their reciprocals show that the number 1 can be expressed as the sum of three unit fractions: 1 = 1/2 + 1/3 + 1/6.
More from Urban Dictionary

trucker's tan 

A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
I had a trucker's tan after driving for 10 straight hours on a sunny day.
Word of the Day on October 5, 2026
The phenomenon where adults salivate at children's toys
Every time I walk into the toy aisle, I catch myself kidulting over the latest action figures and LEGO sets!
kidulting by Emotional Cruiser October 12, 2025
Word of the Day on October 4, 2026
British slang for a scientist or technical expert, esp . when the speaker is not certain of the expert’s specific field of study. Not necessarily derogatory, but typically used by persons without a technical background. In the US, the equivalent would be “egghead”, “squint”, or “geek.”

Origin of the word is unknown. Started sometime in World War 2. Given the typical evolution of British slang, could easily have started because what these experts did was confusing or “baffling” to the common person.
According to the boffins downstairs, the murderer used a serrated blade.
Boffin by Agnon February 11, 2023
Word of the Day on October 3, 2026

Pee Calculus

When you have to pee in a movie but don’t want to miss anything, and must do the following mental equation: will the amount I have to pee cause enough discomfort to diminish my attention capacity for the remainder of the movie to an extent which is greater than the amount of the movie I would miss by making a mad dash to the restroom.
I saw Satantango last night, wonderful film but by the 5th hour I had to start doing pee calculus.
Pee Calculus by anorlondo October 1, 2026
Word of the Day on October 2, 2026
Load more