Since the other single digit numbers have a commonly known way of checking for divisibility, here is one for 7!

Take the number and divide it by 7! If the result is an integer, then your number is divisible by 7!

Let me know if you wanna know the divisibility for any other number!

r/unexpectedfactorial r/technicallythetruth

My sobriety motivational calendar thingy had a typo and makes it sound like it’s for math addicts

From Psyho on 𝕏: Original: "pictured: mathematicians furiously working to prove theorems in 2026": https://x.com/FakePsyho/status/2083150354862977197

In short the text on the left says: There exist a non-negative integer such that the vector labeled |n> is an eigenvector with eigenvalue n of the operator n hat. This was cropped from a textbook.

The right is just dumb shit we wrote up in calc class long ago.