Math(s)

[yetanotheruser@discuss.tchncs.de]

You are actually allowed to add up infinite series like this.

Only that the infinite series have to be convergent, or else you get little of value. The series in your example oscillates forever (and the oscillation distance remains constant), therefore it diverges.

Take the infinite series 1 + 0 + 0 + 0 + ... and add it like you did:

1 + 0 + 0 + 0 + 0 + ...
___ 1 + 0 + 0 + 0 + ...

And you just get 1 + 1 + 0 + 0 + 0 + ... which is just 2 * (1 + 0 + 0 + 0 + ...)

[hjalamanger@feddit.nu]

Il do it for disability by three and a three digit numbers with the digits a, b and c. The value of that number then is 100a + 10b + c. They concept is the same for nine.

100a + 10b + a mod 3 =
a + b + a

This means that, mod 3, a three digit number is equivalent to the sum of it's digits and therefore preserves disability by 3.

[sudo@lemmy.today]

832 is 800 + 32

800 is obviously divisible by 8, so it can also be negated like the first few digits.
32 is also divisible by 8.

[driving_crooner@lemmy.eco.br]

First step to find 1 + 2 + 3 + ... = -1/12

[zugyuk@lemmy.world]

That's why you always go for multiples of 6 plus or minus 1 that are not multiples of 5 or 11.

[tempermentalanomaly@lemmy.world]

I have discovered a truly marvelous demonstration of this proposition that this comment section is too narrow to contain.

[rebelsimile@sh.itjust.works]

This is how I see it, 30 + 21, doesn’t come up that often obviously, but also we don’t have to love every composite number. In fact, we hates most of them. Add 51 to the pile.

[pfm@scribe.disroot.org]

Reading the beginning of your comment, I was sure you'd end it with "depends how brave you are".

[lennivelkant@discuss.tchncs.de]

Dammit, it was right in the post, why did that take me so long?

[unrepententprocrastinator@lemmy.ca]

All the magic goes when you understand it's 30+21

[vinesnfluff@pawb.social]

"This is called 'maths'. Or 'math' if you're American, as they're only allowed to have one. Due to... I don't know budget cuts or something". — ASHEN, Stuart

[foobarrington@lemmy.world]

Oh yeah? Then what's 34 divided by 17, smart guy?

[southsamurai@sh.itjust.works]

Jesus 42

[foobarrington@lemmy.world]

[c126@sh.itjust.works]

Wait until they find out 68 is also divisible by 17.

[alenalda@lemmy.world]

When I was young I learned that when you add up all the numbers if that number is a multiple of 3 than the original number is also divisible by 3. So 51, 5+1=6 and 6 divisible by 3 and so must 51.

[iknowitwheniseeit@lemmynsfw.com]

Why? 19 is 15+4 but is still prime?

[verito@lemm.ee]

Because 30 and 21 are both divisible by the same number, 3.

[iii@mander.xyz]

I always thought it's 31+20

[unrepententprocrastinator@lemmy.ca]

Exactly 3(10+7)