In the set of Whole numbers  0, 1, 2, 3, 4, 5, 6, ....  there is an amazing rule about composite numbers.
Composite numbers are ones which are not prime; they have at least one factor besides the number itself and 1.


For example:
17 is prime. Its only factors are 1 and 17.
15 is composite, because its factors are 1, 15, AND 3 and 5.

Here's the amazing part:
You can come up with every composite number, no matter how large, by multiplying prime numbers together!

Let's take the number 60 for example. We know it must be composite, because it will divide by 2 as well as by 1 and 60.
The 'prime factors' rule says that there must be some combination of prime numbers that multiply together to give 60.
Here are the first ten prime numbers:  2, 3, 5, 7, 11, 13, 17, 19, 23, 29. Can you make 60 by multiplying some of these together? Here's a hint ... you can use a prime number more than once.

The answer is that you'll get  60 if you multiply  2 x 2 x 3 x 5. Try it.

The rule works for ANY composite number. Here's how you get 124:  124 = 2 x 2 x 31

Now you try one ... find the prime factors of  162

When you think you know the answer, go on to the second page ...




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