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## #1 2012-11-20 12:00:41

mathgogocart
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### post prime numbers!

We will post prime numbers and say something intrssting about the number
So lets start
3!
the unluck number:|

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"Those who feed spambots are spambot conspiarators,and bad people." mathgogocart.

## #2 2012-11-20 17:51:32

anonimnystefy
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### Re: post prime numbers!

2-the only even prime.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón

## #3 2012-11-30 18:59:25

julianthemath
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### Re: post prime numbers!

5-number of fingers on your hand!!!

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## #4 2012-12-01 06:55:59

noelevans
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### Re: post prime numbers!

7  One of the few primes whose reciprocal is easy to remember.

For 1/7:  2*7=14, 2*14=28,  2*28+1=57 ; that is, keep doubling the denominator till you reach
56 then add the numerator to the 56 to get the last two digits of 1/7 which is a repeating .142857.

Of course 1/2, 1/3, 1/5 and 1/11 aren't bad either.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

## #5 2012-12-01 15:19:38

julianthemath
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### Re: post prime numbers!

13- number of different cards in a deck

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## #6 2012-12-07 09:53:41

noelevans
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### Re: post prime numbers!

11 --- one of the few primes larger than 10 that it is easy to multiply by.  To multiply a number, say
3142 by 11 just put a zero in front and behind it, like so 031420 and then add consecutive pairs of
digits (typically from right to left since in some cases there may be carries) and record these sums:
0+3, 3+1, 1+4, 4+2, 2+0 ; that is, 34562.  If a sum exceeds 9 then carry 1 to the next sum for example 23572 ---> 0235720 --->  2 5 8 12 9 2 = 2 5 9 2 9 2; that is, 259292 carrying the 1
from the 12 into the 8 in the next column to the left.  With a little practice this can be done quickly
in one's head.

Last edited by noelevans (2012-12-07 09:55:06)

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

## #7 2012-12-07 10:02:15

anonimnystefy
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### Re: post prime numbers!

19-the first prime with the sum of its digits equal to 10.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón

## #8 2012-12-07 10:04:56

bobbym
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### Re: post prime numbers!

23

John Forbes Nash's favorite prime number.

In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.

## #9 2012-12-07 10:07:18

anonimnystefy
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### Re: post prime numbers!

Boy, was that guy an ugly fellow!

97-largest prime below 100.

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón

## #10 2012-12-07 10:12:48

mathgogocart
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### Re: post prime numbers!

131-the number that is ALSO PSELLED BCAKWARDS...OMG

bbcode;.Uhhhhhhhhh im bored.
"Those who feed spambots are spambot conspiarators,and bad people." mathgogocart.

## #11 2012-12-08 12:02:03

noelevans
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### Re: post prime numbers!

13 --- a baker's dozen.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

## #12 2012-12-08 12:32:50

anonimnystefy
Real Member

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### Re: post prime numbers!

23-number of characters in "greengrocers apostrophe"

The limit operator is just an excuse for doing something you know you can't.
“It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman
“A secret's worth depends on the people from whom it must be kept.” ― Carlos Ruiz Zafón

## #13 2012-12-08 12:49:18

noelevans
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### Re: post prime numbers!

Three digit numbers with two 3's and one 1 or with two 1's and one 3.  Only one of them is NOT a
prime.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

## #14 2012-12-08 13:07:18

noelevans
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### Re: post prime numbers!

2 --- the only number for which any positive integer can be written as a sum of non-negative powers of that number alone using each power of the number no more than once.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

## #15 2012-12-09 03:57:56

mathgogocart
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### Re: post prime numbers!

101-1-1=0-the first sensible number

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"Those who feed spambots are spambot conspiarators,and bad people." mathgogocart.

## #16 2012-12-14 17:04:34

julianthemath
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### Re: post prime numbers!

My answer

Last edited by julianthemath (2012-12-14 17:05:18)

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## #17 2012-12-17 03:41:41

mathgogocart
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### Re: post prime numbers!

111 3 digits repeated trpile

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## #18 2012-12-18 15:58:44

julianthemath
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### Re: post prime numbers!

Mathgogocart, 111 is not prime. It is divisible by 1, 3, 37, 111 (ay be incomplete).

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## #19 2013-01-08 12:27:05

mathgogocart
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### Re: post prime numbers!

2

bbcode;.Uhhhhhhhhh im bored.
"Those who feed spambots are spambot conspiarators,and bad people." mathgogocart.

## #20 2013-01-08 12:29:40

bobbym
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### Re: post prime numbers!

I think you already picked 2.

101 - a room with a special meaning.

In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.

## #21 2013-01-12 20:42:44

julianthemath
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### Re: post prime numbers!

#### bobbym wrote:

101 - a room with a special meaning.

What is the special meaning?
17-the sum of the first four primes.

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## #22 2013-01-12 23:15:43

scientia
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### Re: post prime numbers!

According to the Old Testament, 31 kings were defeated by Joshua after the children of Israel had crossed the river Jordan (Joshua 12:9–24).

## #23 2013-01-13 05:38:21

bobbym
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### Re: post prime numbers!

1111111111111111111

The second repunit that is prime.

#### julianthemath wrote:

What is the special meaning?

You are a little young yet but some day you will read 1984.

In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.

## #24 2013-01-13 11:05:42

julianthemath
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### Re: post prime numbers!

Oh, okay.
113-the 30th prime.

Buy 1 for \$1, for \$0.50, for \$3, for \$2.50, for \$1.25, for \$0.25, and for \$5.
Come on, buy a smiley!

## #25 2013-01-13 11:26:51

bobbym
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### Re: post prime numbers!

11111111111111111111111 the 3rd repunit that is a prime.

In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.

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