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Prime Time |
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Do you think prime numbers are a little more interesting now? The better you get at understanding them, the easier math will be for you. If you're still in elementary school, you use prime numbers to work with fractions. Every time you're looking for the lowest common denominator or the greatest common factor, you're using what you know about prime and composite fractions. When you work in algebra, being able to factor equations requires you know how factors and products work and that requires being fast with primes and composites.
Could you find that Mersenne prime? It's 31. 32 is a power of 2 (2x2x2x2x2 or 2 to the 5th) and 31 is one less than that. Be sure to check out www.mersenne.org. Those folks REALLY like prime numbers!!
So, why isn't 1 prime? Many people think that one used to be prime and then some math king decided it wasn't--probably just to confuse everyone. Actually, one hasn't been prime since ancient Greece. The ancient Greeks thought that one wasn't even a number. To them, one was the "principle of number." It was from one that all other numbers came. There was disagreement among Greek mathematicians about whether two was a prime. Today, we agree with Euclid and Aristotle that two is prime but the Pythagoreans (a school of philosophy and mathematics most famous for the equation about the hypotenuse of a right triangle--a squared plus b squared equals c squared) thought that two was not a number but the "principle of even."
Many people have spent a lot of time trying to find patterns to help find more prime numbers. No pattern has ever been found. The triangle below has the square numbers in blue along the right side. The prime numbers are in red. Every time you think there is a pattern, it falls apart when you extend it. Maybe that's why mathematicians are so interested in prime numbers--they want patterns and primes aren't cooperating!
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