i think it is because
1 is it self
and 1 is 1
2007-10-25 23:29:29 · 14 answers · asked by Bumumble 3 in Science & Mathematics ➔ Mathematics
well why is it that in primary school we had the chart of primary numbers and 1 was on there?
2007-10-25 23:34:30 · update #1
No, prime numbers are by definition greater than one.
Think of when we break down integers into their prime factors. It wouldn't be useful to have one as a prime, so it's excluded from consideration.
On a side note, from Wikipedia: "Until the 19th century, most mathematicians considered the number 1 a prime."
2007-10-25 23:49:54 · answer #1 · answered by Ben 3 · 1⤊ 0⤋
A prime number is a positive integer that has exactly two positive integer factors, 1 and itself. For example, if we list the factors of 28, we have 1, 2, 4, 7, 14, and 28. That's six factors. If we list the factors of 29, we only have 1 and 29. That's two factors. So we say that 29 is a prime number, but 28 isn't.
Note that the definition of a prime number doesn't allow 1 to be a prime number: 1 only has one factor, namely 1. Prime numbers have exactly two factors, not "at most two" or anything like that. When a number has more than two factors it is called a composite number.
http://mathforum.org/dr.math/faq/faq.prime.num.html
I tend to agree with you, too, though. I seem to remember being taught in school that 1 *was* a prime number, but that was a loooong time ago.
Here's another link I found. This one states that "Nobody is sure whether 1 is prime or not!"
http://www.murderousmaths.co.uk/books/primeflash/index.htm
2007-10-25 23:44:48 · answer #2 · answered by ~RedBird~ 7 · 1⤊ 0⤋
No, 1 is not a prime number. A prime number is a number with only TWO factors 1 and itself.
2007-10-25 23:32:57 · answer #3 · answered by mr_maths_man 3 · 2⤊ 0⤋
No. By definition, a prime number is not 1.
2007-10-25 23:35:26 · answer #4 · answered by Anonymous · 1⤊ 0⤋
1 is not considered to be a prime number even though it is divisible by 1 and itself.
The first prime number is 2. I am afraid your primary school was not correct.
The fact that 1 is not a prime was not always the case. Several hundred years or so ago it was considered a prime. I think Euler was the first mathematician to argue it was not.
2007-10-26 02:05:42 · answer #5 · answered by Anonymous · 0⤊ 0⤋
0 and 1 are special numbers.
The first prime number is 2.
2007-10-25 23:38:25 · answer #6 · answered by ptolemy862000 4 · 1⤊ 0⤋
1 is not a prime number for the reasons stated above.
A Primary number is not the same as a prime number.
2007-10-25 23:38:37 · answer #7 · answered by Anonymous · 1⤊ 0⤋
N O
It can me divided with 1 and itself, but its not considered to be prime number. The first prime number is 2.
Primary numbers are something different. They are{1,2,3,4,5,6,7,8,9,10....}
2007-10-26 01:01:59 · answer #8 · answered by Anonymous · 1⤊ 0⤋
no, 1 is not a prime number because it has only one factor and that is one.
Prime numbers have two factors. for example- 2-1,2
2007-10-25 23:33:06 · answer #9 · answered by sahil d 1 · 1⤊ 0⤋
1 is neither a prime number nor a composite number.
2007-10-25 23:39:07 · answer #10 · answered by Anonymous · 1⤊ 0⤋