/sci/ - Science & Math

[Anonymous No.11022382]

have you noticed that the left digit increases by one and the right digit decreases?
09
18
27
36
45
56
...

[Anonymous No.11022391]

[Anonymous No.11022393]

>>11022382
Let me blow your mind:

The summation of the digits of any multiple of 9 is divisible by 9.

Ex. 9*15462=139158, 1+3+9+1+5+8 = 27

[Anonymous No.11022454]

>>11022393
I don't see what's so great about that

[Solivagus (Polynomial Philosop(...) No.11022458]

>>11022393
>The summation of the digits of any multiple of N is divisible by i.

[Anonymous No.11022486]

>>11022382
only works up to 90.

[Anonymous No.11022498]

>>11022454
It's a great way to test if a number is divisible by 9. Can you find such a simple rule to check if a number is divisible by 7?

[Anonymous No.11022500]

>>11022486
099
108
117
...

[Anonymous No.11022538]

>>11022500
>left digit increases by one

[Anonymous No.11022552]

>>11022538
Second from the right

[Anonymous No.11022568]

>>11022382
I always used to work out the nine times tables like this: if n is the other number you're multiplying by, the 1st digit n-1 and the second is 10-n.
Doesn't work past ten tho.

Also 9*6 is 54 fool

[Anonymous No.11022589]

>>11022382
...90..99...
bs

[Anonymous No.11022606]

>>11022498
Yeah. Just divide it by 7. You stupid fuck.

[Anonymous No.11022612]

>>11022606
Good luck, dividing 12468742157853 by 7. But I can tell you with virtually no effort that it's divisible by 3.

[Anonymous No.11022746]

>>11022393
Hurr Durr I mean no shit

[Anonymous No.11022754]

>>11022382
Hmm, it's almost like 9 = 10 - 1

[Anonymous No.11022794]

>>11022382
>not using numbers with digits that sum up to the base in which the numbers are notated
What kind of /sci/ck fuck are you? No worries though. It is still a pretty interesting OPen (open OP). And here's all with 3 digits.

000 109 208 307 406 505 604 703 802 901
019 118 217 316 415 514 613 712 811 910
028 127 226 325 424 523 622 721 820 929
037 136 235 334 433 532 631 730 839 938
046 145 244 343 442 541 640 749 848 947
055 154 253 352 451 550 659 758 857 956
064 163 262 361 460 569 668 767 866 965
073 172 271 370 479 578 677 776 875 974
082 181 280 389 488 587 686 785 884 983
091 190 299 398 497 596 695 794 893 992

[Anonymous No.11022963]

>>11022606
Based

[Anonymous No.11022975]

>>11022382

"Grothendieck's folly" was an early note that he'd published in which he observed that

[eqn] (111 \; 111 \; 111)^2 = 12 \; 345 \; 678 \; 987 \; 654 \; 321 [/eqn]

[Anonymous No.11022989]

>>11022975
>Grothendieck's folly
No results on duckyduck.

[Anonymous No.11023044]

https://youtu.be/Q53GmMCqmAM