## Ahad, 13 Februari 2011

### (2.5) Prime Factor

Previous lesson we learn what is factor and how to determine factors of a given number. A factor of a given number is the number that can be divided with the given number exactly.

Based on the factors of given number, we can determine the prime factors of the given number.
But, did you know what is prime factor?

By using this method, you have to list out all the factors of 28.
Based on the factors that you obtained, determine which number is the prime number.
2 and 7 are prime number.
Therefore, it means that 2 and 7 are the PRIME FACTORS of 28.

Beside that, you can use algorithm method whereby you use prime number as the divisor.
The rule is, you have to divide the given number with the smallest prime number (exact division) until you get 1.

NOTE:
28 divide with 2 (smallest prime number) you will get 14.
Then, 14 divide with 2 = 7
7 divide with 7 because 7(divisor) is the smallest prime number that can be divided to obtain exact division.
Derive your calculation until you get 1.

In order to determine whether a prime number is a prime factor of a given number, just divide the given number with the given prime number. If there is exact division, then it is a prime factor of the given number.

But, if you did not get exact division (you get remainder), then it is not a prime factor of the given number.

~  MATH is EASY  ~