1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321
1111 x 1111 = 1234321
11111 x 11111 = 123454321
111111 x 111111 = 12345654321
1111111 x 1111111 = 1234567654321
11111111 x 11111111 = 123456787654321
111111111 x 111111111 = 12345678987654321

Mind blown

Maths is my favourite subject - because of the beautiful symmetry of it.

Thought you were about to embark on a big gear ratio discussion there!
Never come across that before, good find

my 12 year daughter told me today that if you were able to fold a piece of paper in half 42 times it would reach the moon, which seemed like bollocks to me but a smarter mind than me has proved it to be true

https://wwvv.codersrevolution.com/blog/ ... h-the-moon

maybe this is why Douglas Adams decided in Hitchhikers Guide to the Galaxy that 42 was "The answer to the ultimate question of life, the universe and everything”

holdsteady wrote: ↑Sun Nov 14, 2021 5:25 pm my 12 year daughter told me today that if you were able to fold a piece of paper in half 42 times it would reach the moon, which seemed like bollocks to me but a smarter mind than me has proved it to be true

https://wwvv.codersrevolution.com/blog/ ... h-the-moon

maybe this is why Douglas Adams decided in Hitchhikers Guide to the Galaxy that 42 was "The answer to the ultimate question of life, the universe and everything”

There's a similar one from classical tales about a servant wanting to be paid one grain of rice on day one, two on day two, four on day three, etc. Doesn't sound too onerous except that by day 54 the amount of rice exceeds the current world rice production of 500 million tonnes! (in addition the previous 53 days come to 500 million tonnes minus one grain) - https://www.mathscareers.org.uk/the-ric ... rd-legend/

Did Doug A meet your daughter then? . If she came up with the 42 idea she's famous now!

Think I read somewhere once that it's actually physically impossible to fold a piece of paper more than 7 times no matter how big it is, even if it's the size of the universe.

RIP wrote: ↑Sun Nov 14, 2021 9:29 pm Think I read somewhere once that it's actually physically impossible to fold a piece of paper **in half **more than 7 times no matter how big it is, even if it's the size of the universe.

Seeing as this is maths chat pedantry is necessary.

benconnolli wrote: ↑Sun Nov 14, 2021 10:59 pm

RIP wrote: ↑Sun Nov 14, 2021 9:29 pm Think I read somewhere once that it's actually physically impossible to fold a piece of paper **in half **more than 7 times no matter how big it is, even if it's the size of the universe.

Seeing as this is maths chat pedantry is necessary.

Agreed. Thank you Ben.

Take any multiple of 9
Add its digits together
If the result has more than one digit, go back to the previous step.
The final, single digit, result is 9

As far as I remember, Douglas Adams was a computer geek. 42 is the ascii code for an asterisk. An asterisk is often used as a wildcard, ie it can be anything. So the answer to life the universe and everything is 'anything you want it to be'.

Possibly all the above, he just saw that 42 was the answer to a few big questions. so put it in his book. which he also claimed he got the idea in a Austrian Ditch whilst inter-railing/bumming round those parts with The . Hitchhiker guide to Europe. He looked up & saw the milky way, put 2 and two to get her to get 2x2 1st digit and 2x2/2 as the 2nd. hence.... forty two..... now there's possibly no truth to this idea but it made a goo preface to a book or two..
ditches and 42 predate bikepacking (not) as we know it. to para phrase & mix sci-fi nerd/geek sub niches.

belugabob wrote: ↑Mon Nov 15, 2021 1:49 pm Take any multiple of 9
Add its digits together
If the result has more than one digit, go back to the previous step.
The final, single digit, result is 9

That works for any base N and any multiple of its N-1.

I.e for base 8, 2x7 = 16, 3x7 = 25, etc.

whitestone wrote: ↑Mon Nov 15, 2021 10:09 pm

belugabob wrote: ↑Mon Nov 15, 2021 1:49 pm Take any multiple of 9
Add its digits together
If the result has more than one digit, go back to the previous step.
The final, single digit, result is 9

That works for any base N and any multiple of its N-1.

I.e for base 8, 2x7 = 16, 3x7 = 25, etc.

Some brilliant maths nerderey here: https://youtube.com/c/numberphile

EG: https://youtu.be/HJ_PP5rqLg0