Date: Mon, 27 Oct 1997 14:39:09 0500
My name is Melissa and I am a student. I have a couple of question on the middle / secondary level. I would appreciate any help you could give me.
 Why isn't 1 a prime number?
 How can the absolute value of a number be negative?
Thank you very much,
Melissa
Hi Melissa,

Much of the work of mathematicians and scientists involves decomposing complex objects into simpler parts. Scientists sometimes decompose complex molecules into simpler molecules or atoms, and mathematicians at times find it useful to write numbers as the product of smaller numbers, as 60=2*30=4*15=2*2*3*5. Writing 60=2*2*3*5 is the best you can do since the numbers 2, 3 and 5 are primes and cannot be decomposed further. To write 60=1*2*2*3*5 is more complex and the 1 doesn't give you any useful information because any number is divisible by 1. Since we want the decomposition of a positive integer into primes to be the "simplest" form, we say that 1 is not a prime.

It can't! The absolute value of a number is the distance from that number to the origin and thus it can not be negative.
Cheers,
Penny
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