# The Last Digit of Pi.



## DeleterJoe (Sep 1, 2012)

I read on another thread, now dead and closed, about someone conjecturing that the last digit of pi was 0, and I thought well that's stupid of course there is no last digit of pi since it's an irrational number and continues forever... then a thought occurred, the last digit of pi if there were one, would be just that "1" it would be the point at which there was a realization that the number sequence actually did start over. or perhaps it could be 2, 3, 4, 5, 6, 7, 8, 9, 0. If not 1, I mean if there were to be a last digit it would have to be one of those "10" numbers.


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## emolover (Sep 1, 2012)

The last number is 4.


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## ThomasJE (Sep 1, 2012)

DeleterJoe said:


> I mean if there were to be a last digit it would have to be one of those "10" numbers.



That's like saying if you were to get a PLL, it would be A, U, H, Z, N, J, R, T, F, Y, G, E or V.

Anyway, irrational means a number goes on forever WITHOUT a pattern. So, 10/3 is rational. Pi is irrational, so we don't know the last digit.


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## brunovervoort (Sep 1, 2012)

It's 5, no doubt.


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## Stefan (Sep 1, 2012)

ThomasJE said:


> irrational means a number goes on forever WITHOUT a pattern.



Here's an irrational number with a simple pattern:

1.01001000100001000001000000100000001000000001...
(always one more 0 before the next 1)


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## Dene (Sep 2, 2012)

emolover said:


> The last number is 4.



You win this thread.


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## ThomasJE (Sep 2, 2012)

Stefan said:


> Here's an irrational number with a simple pattern:
> 
> 1.01001000100001000001000000100000001000000001...
> (always one more 0 before the next 1)



OK, a repeating pattern.


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## Dacuba (Sep 3, 2012)

ThomasJE said:


> OK, a repeating pattern.



A rational number is any number that can be written as p/q, assuming p and q are real.
afaik. Don't yell at me.


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## ThomasJE (Sep 3, 2012)

Dacuba said:


> A rational number is any number that can be written as p/q, assuming p and q are real.
> afaik. Don't yell at me.



Makes sense.


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## Stefan (Sep 3, 2012)

Dacuba said:


> A rational number is any number that can be written as p/q, assuming p and q are *real*.



Not quite.

And I don't see how that characterization would be useful for the topic of this thread.


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## uberCuber (Sep 4, 2012)

Dacuba said:


> A rational number is any number that can be written as p/q, assuming p and q are real.



This would mean that pi is rational because you can write it as pi/1, and both pi and 1 are real.


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## mdolszak (Sep 4, 2012)

From Dictionary.com:

Rational number - a number that can be expressed exactly by a ratio of two integers.

Pi is not an integer; therefore pi/1 is not a rational number.


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## cowabunga (Sep 4, 2012)

must... make perfect circle!

its 0 btw


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## Stefan (Sep 4, 2012)

mdolszak said:


> From Dictionary.com:
> 
> Rational number - a number that can be expressed exactly by a ratio of two integers.
> 
> *Pi is not an integer; therefore pi/1 is not a rational number.*



0.5 is not an integer; therefore 0.5/1 is not a rational number.

Right?


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## Dacuba (Sep 4, 2012)

I am so freaking scared of quoting you cause I know you are way smarter than me 



Stefan said:


> 0.5 is not an integer; therefore 0.5/1 is not a rational number.
> 
> Right?



0.5/1 is a rational number, because it is the same as 1/2 and therefore can be expressed as a ratio of two integers, which covers the defintion of mdolszak.
But you can't form pi/1 to a ratio with two integers, so pi/1 is not a rational number.


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## Stefan (Sep 4, 2012)

Dacuba said:


> But you can't form pi/1 to a ratio with two integers



Are you sure? Proof, please!



Spoiler



Just kidding. And yeah, that's how he should have written it.

And lol at you being scared of me


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## Sa967St (Sep 5, 2012)

Dacuba said:


> A rational number is any number that can be written as p/q, assuming p and q are *integers, and q is non-zero*.
> afaik. Don't yell at me.


FTFY.


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## Rune (Sep 5, 2012)

Stefan said:


> Here's an irrational number with a simple pattern:
> 
> 1.01001000100001000001000000100000001000000001...
> (always one more 0 before the next 1)



A remarkable number. After a while you´ll find a string of an infinite number of zeros in it. But still, the number does not end on a zero. Or does it?


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## Stefan (Sep 5, 2012)

Rune said:


> After a while you´ll find a string of an infinite number of zeros in it.



I don't think so. You only get arbitrarily long finite zero-strings.


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