## Tuesday, November 22, 2011

### Prime factor decomposition of a number.

Finding the prime factor decomposition of a number is simple,once you get your head around it .First you begin with a number [eg:40], you then split it into two numbers , then multiply it and you should get 40.Because 2 is a prime number , you circle it and then split 20.You continue like this until both numbers are circled.You then give ,your answer by using the circled prime numbers.So the sum is 40=2x2x2x5 or even 40=2 cubed times 5

1. Brilliant - well laid out and simple to follow. I learned from it.

2. Well done both of you! Now can you explain how to find Lowest Common Multiples & Highest Common Factors? Or maybe find a video that would help?

3. Excellent work guys. I remember learning about prime numbers when I was at school.

4. Even I learnt a bit :]

5. Haha - well done Adeel!

6. Mrs Mackie . AustraliaNovember 22, 2011 at 6:54 PM

Wow you guys have taught me something new today. I have always liked prime numbers. Love your blog BTW.

7. Some often-confused facts about prime numbers
Zero is not a prime a number
The number one, 1, is also not a prime number. Although the definition of a prime number seems to apply to 1, you have to count 1 twice --sorry no 'double dipping' for prime numbers. 1 is not prime.
The only even prime number is 2, because all of the other even prime numbers are multiples of 2 and therefore violate the definition of a prime number

8. Definition:

A prime number is a number whose only factors are 1 and itself. That means there is no whole number that evenly divides the prime number.

9. Here is the website I used.

http://www.mathwarehouse.com/arithmetic/numbers/prime-number/index.php

If you really want to know more about primes then you should check out Marcus du Sautoy's website and book http://www.musicoftheprimes.com/

It gets complicated but is absolutely fascinating!

11. Very clear and simple. Well done!

Pablo Demarchi
Argentina

12. I love seeing our school be a psrt of this. I've been using www.khanacademy.org to look at Maths problems and advice, but this is great. Keep up the good work Mr Stucke's class. By using this often your grades will soar! Well done everyone! Mrs Shore

13. This is a great way of arriving at prime factors for a number. With 2 being the only prime even number, it was dealt with in the first step only leaving the need to calculate other factors. In your example, this resulted in a series of 2 before we saw the different prime number (5) appear.

Ross Mannell (teacher)
NSW, Australia

14. Hugely impressed! From my "English" subject point of view I always considered that decomposition was something to do with rotting. I've learnt something here!

15. In a way it's the same meaning. Prime factor Decomposition is the process of splitting a number up into it's most basic numerical building blocks. A bit like something rotting away!

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17. Hi! My name is Eye and I will be quad blogging with you guys! :) Your description of prime factorization is very easy to follow through. It was also very helpful that you provided a visual example that accompanies your description really well.

18. Hello! My name is Sally, a student in Ruamrudee International School and your quad blogging partner:D I like the way you post both decorative and informative pictures to support the math knowledge of prime factorization. Your description on the topic is easy to understand. I also like the clear way you showed the process including circling the prime number, it makes math easier!

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