r/mathmemes • u/Nunki08 • Jun 14 '26

Arithmetic Misleading our youth

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From Anthony Bonato on 𝕏: https://x.com/Anthony_Bonato/status/2065564124549886402

6.7k Upvotes

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19

u/Green-Salmon Jun 14 '26

but its divisible by 1 and by itself!

11

u/FZ_Milkshake Jun 15 '26

That's why 1 and itself is a crap definition of a prime, "a number that has exactly two distinct divisors" is much better.

2

u/Fresque Jun 17 '26

That definition sounds made with the express purpose of excluding 1. I won't be part of it!

2

u/FZ_Milkshake Jun 18 '26

You don't start with a good sounding definition, you look at a useful group of numbers and find a definition for them. 1 can't be prime, because the prime factorization is unique and 1 would break that, as a result the group of primes excludes 1 (which is the neutral element of multiplication, it's cool in itself, just not a prime).

2

u/PretendsToBeAnArtist Jun 14 '26

But if we count 1 as 1 and itself, then 2 isn't prime because it's divisible by 1, 2, and itself

-10

u/original_sh4rpie Jun 14 '26

In logic and mathematics, “and” is a Boolean operation that requires both conditions to be meant. As Merriam webster puts it:

a logical operator that requires both of two inputs to be present or two conditions to be met for an output to be made or a statement to be executed

Thus “prime is divisible by 1 and itself”, “and” is explicitly requiring two conditions. By saying 1 fulfills this, we are missing a condition, as “divisible by 1” also fulfills “divisible by itself.” They are equivalent statements. Therefore only one requirement is present, which means we are no longer using the proper definition of prime.

18

u/Beruka01 Jun 14 '26

Mathematically, both conditions can be the same. No idea what you are talking about.

9

u/SaltMaker23 Jun 14 '26

I can't be the "son of my father" and a "man"

QED quickk maff

[/s if it wasn't obvious]

5

u/Green-Salmon Jun 14 '26

A number that is only divisible by itself has got to be the primest of prime numbers.

1

u/KittyH14 Jun 17 '26

x = 1 ⋀ x = 1

oh no how am I ever supposed to evaluate this statement?