# Math Is Fun Forum

Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

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## #1 2007-03-07 04:30:50

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

### 2424[b]2[/b]4242 in $\pi$

If you choose to call the 1 in 3.14, the
zeroth digit of pi, then an amazing thing
happens.
The 242424th digit of pi, with the
zeroth digit being the 1 after the
decimal is the exact middle of
a string of nine digits, those
being:  242 424 242

And usually, in the first million digits of
pi, you can find most any 5 digit number,
and lots of 6 digit numbers, but a
nine digit number that is so cool!!!!

Last edited by John E. Franklin (2007-03-07 04:31:25)

igloo myrtilles fourmis

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## #2 2007-03-07 04:39:25

Sekky
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Registered: 2007-01-12
Posts: 181

### Re: 2424[b]2[/b]4242 in $\pi$

if I recall correctly, there is a string of six 9s in the first thousand digits

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## #3 2007-03-07 04:58:04

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: 2424[b]2[/b]4242 in $\pi$

In eulers constant "e", right after 7 a nifty pattern occurs that makes it easy to remember the first 10 digits:
2.7-1828-1828-

A logarithm is just a misspelled algorithm.

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## #4 2007-03-07 08:02:29

Patrick
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Registered: 2006-02-24
Posts: 1,005

### Re: 2424[b]2[/b]4242 in $\pi$

Also the next part is rather easy 45-90-45, which you just have to link to triangles and it'll get stuck in your head pretty easily

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## #5 2007-03-07 08:27:41

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

### Re: 2424[b]2[/b]4242 in $\pi$

Then its 2 3 5  the first three prime numbers. That takes us to the first 18 decimal places: e = 2.718281828459045235

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## #6 2007-03-07 13:52:57

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

### Re: 2424[b]2[/b]4242 in $\pi$

Yeah, I knew about the 1828 1828, but not the 45-90-45, nor the 2,3,5 primes.
Anyone know this? 8214808651 32382 06647, not positive on the 32382, but the 8214808651 should be right.

igloo myrtilles fourmis

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## #7 2007-03-08 20:01:42

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: 2424[b]2[/b]4242 in $\pi$

According to my memory of pi, that should be 8214808651 32823 06647.

I didn't use any mnemonics for memorising e or pi. You'll all find it hard to actually believe me, but it becomes very, very simple when you just try to memorise 4 digits at a time. Try and memorise a '6' digit group as a marker. It helps.

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## #8 2007-03-08 20:21:01

lightning
Real Member
Registered: 2007-02-26
Posts: 2,060

### Re: 2424[b]2[/b]4242 in $\pi$

pi is 3.1415927 (i think) well thats what my dad told me.

Zappzter - New IM app! Unsure of which room to join? "ZNU" is made to help new users. c:

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## #9 2007-03-08 22:00:02

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: 2424[b]2[/b]4242 in $\pi$

It would be that if it was rounded up. Pi is not 3.1415927. It goes on forever, to make it simple.

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## #10 2007-03-08 23:42:50

Sekky
Member
Registered: 2007-01-12
Posts: 181

### Re: 2424[b]2[/b]4242 in $\pi$

Devanté wrote:

According to my memory of pi, that should be 8214808651 32823 06647.

I didn't use any mnemonics for memorising e or pi. You'll all find it hard to actually believe me, but it becomes very, very simple when you just try to memorise 4 digits at a time. Try and memorise a '6' digit group as a marker. It helps.

That is correct

...093844609550582231725359408238481117450...

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## #11 2007-03-08 23:46:51

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

### Re: 2424[b]2[/b]4242 in $\pi$

I think I might get back to remembering pi, been very busy/lazy lately.

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## #12 2007-03-09 03:25:49

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

### Re: 2424[b]2[/b]4242 in $\pi$

To lightning:  The reason we are using 8214808651 and not 14159265 is because we are talking about digits of pi that are 100 digits down into the number.  So it is not the beginning part.
I was just testing people's memory, to see if they recognized that far in.
And then I made a tiny boo-boo, it's 82148 08651  32823 06647.
I memorize usually in groups of 5, which I do by saying them aloud, but I like the idea of doing it by 4's a lot too, maybe I'll try that out on 2.718 e number.

igloo myrtilles fourmis

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## #13 2007-03-09 03:33:36

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

### Re: 2424[b]2[/b]4242 in $\pi$

I adjust my memorizing technique where it suits the number, for instance, I would remember like this:

6406286208998628

And that also means that a number may be part of 2 groups:

3.1415926

For me 5 is part of the 3.1415, as it progresses up from 3 to 4 to 5, but it is also a necessary part of 5-9 and 2-6 to keep a difference of 4 between each of the two which is how i've remembered them.

-.- maybe i should just learn in groups of five.

Yes.

Nevermind.

Last edited by Toast (2007-03-09 03:34:21)

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## #14 2007-03-09 05:56:22

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: 2424[b]2[/b]4242 in $\pi$

In psych a read about a technique called chunking where you break up something to memorize into a handfull of small pieces that each containing a larger amount of data. For instance, if might be hard to memorize a random collection of 24 letters, but if you can remember 6 four letter words that contain those letters, memorizing just got 4 times easier!

Perhaps it would be a good idea to memorize pi as a collection of 3 or 4 digit numbers. Or maybe as a collection of 7 digit "phone" numbers. If you can memorize 7 phone numbers after the three, thats 50 digits right there.

Last edited by mikau (2007-03-09 06:00:22)

A logarithm is just a misspelled algorithm.

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## #15 2007-03-09 06:27:50

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: 2424[b]2[/b]4242 in $\pi$

Here are my groups up to 100 (apologies if this is going off-topic):

3.14159 2653 5897 9323 846264 338 3279 502884 1971 693993 7510 582 0974 944 5923 0781 6406 2862 0899 8628 0348 2534 2117 0679

I won't go further, but you sort of see how it works.

I will look for Sekky's string of six 9s.

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## #16 2007-03-09 06:34:30

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: 2424[b]2[/b]4242 in $\pi$

Just threw this together.

Memorize this fake flyer and you know 50 digits of pi!

A logarithm is just a misspelled algorithm.

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## #17 2007-03-09 06:36:51

Devantè
Real Member
Registered: 2006-07-14
Posts: 6,400

### Re: 2424[b]2[/b]4242 in $\pi$

Why is the food not garenteeed?

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## #18 2007-03-09 06:39:17

mikau
Member
Registered: 2005-08-22
Posts: 1,504

### Re: 2424[b]2[/b]4242 in $\pi$

Anyways, I think 7 digit phone numbers have a certain rythem to them that make them easy to remember. This flyer only goes from a to g, 7 letters. It would be fairly easy to extend the flyer all the way to z, and that would be 182 digits of pi!

The pictures should help you form visual and verbal associations with the numbers, that should facilitate memorization and recollection.

Last edited by mikau (2007-03-09 06:47:40)

A logarithm is just a misspelled algorithm.

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