true

Take Class I-V Tuition from the Best Tutors

• Affordable fees
• 1-1 or Group class
• Flexible Timings
• Verified Tutors

Search in

A
Amrtha S.
06/04/2017 0 0

# Some numbers can be evenly divided only by 1 and themselves. These are prime numbers. Factors that are prime numbers are called prime factors.

Every whole number greater than one is either a prime number, or can be described as a product of prime factors.

 Examples: 10 is the product of the prime factors 2 x 5 11 is a prime number 12 is the product of the prime factors 2 x 2 x 3 324 is the product of the prime factors 2 x 2 x 3 x 3 x 3 x 3 700 is the product of the prime factors 2 x 2 x 5 x 5 x 7 701 is a prime number 2103 is the product of the prime factors 3 x 701

To find the prime factors of a given number, follow these steps:

1. See if the number is a prime number. If it's below 1000, use the table of prime numbers. If it is prime, add it to the list of prime factors, and you're done.
2. If it's not prime, try dividing it by a prime number, starting with 2.
• If it divides cleanly, with no remainder, then add that prime to the list of prime factors. Take the quotient as your new number to work with, and return to step 1.
• If it does not divide cleanly, return to step 2, but move on to the next prime on the list.
 Example: Prime factors of 700 700 ÷ 2 = 350, with no remainder. Add 2 to the list of prime factors. 350 ÷ 2 = 175, with no remainder. Add 2 to the list of prime factors. 175 ÷ 2 = 87.5. It doesn't divide cleanly, so we go to the next prime number. 175 ÷ 3 = 58.33. It doesn't divide cleanly, so we go to the next prime number. 175 ÷ 5 = 35, with no remainder. Add 5 to the list of prime factors. 35 ÷ 5 = 7, with no remainder. Add 5 to the list of prime factors. 7 is a prime number. Add 7 to the list of prime factors, and we're done. The prime factors of 700 are 2 x 2 x 5 x 5 x 7.

Be sure to check at each step to see if the number you have is a prime. The next example illustrates why:

 Example: Prime factors of 2103 2103 ÷ 2 is 1051.5. It doesn't divide cleanly, so we go to the next prime number. 2103 ÷ 3 is 701, with no remainder. Add 3 to the list of prime factors. The table of prime numbers will tell you that 701 is a prime. Add 701 to the list of prime factors, and we're done. The prime factors of 2103 are 3 x 701.

If we didn't notice that 701 was a prime, we'd have gone on to check 5, 7, 11, 13, and so on, going through 120 more primes before getting done. So be sure to check the quotient every time before proceeding.

(As you might imagine, this method is designed for smaller numbers. It's too time-consuming for very large ones.)

0 Dislike

## Other Lessons for You

CONCEPTUAL CLARITY
WHILE STUDYING ANY TOPIC MAKE SURE THAT AVOID MULTIPLE SOURCES. INSTEAD PICK UP ONE STANDARD SOURCE AND THE CONTENT OF WHICH YOU CAN COMPREHEND. READ IT MULTIPLE TIMES...FRAME A PICTURE IN MIND....ANALYSE...

Why is 2 not a composite number?
A composite number is a positive integer that can be formed by multiplying together two smaller positive integers. Equivalently, it is a positive integer that has at least one divisor other than 1 and...

What is mass?
What is mass? Mass is a scientific measure of the amount of matter an object is made up of. No matter where you are at given moment in time, mass is constant. So, whether you're walking to the shop to...

Difference between folate and folic acid
1. Folate or folic acid is a type of vitamin B, also referred to as vitamin M, vitamin B9, Vitamin Bc, pteroyl-L-glutamate as well as pteroyl-L-glutamic acid. 2. In pure chemistry, the term folate is...

Maths is fun
Encourage your child to do day to day calculations like at grocer , milkman etc. He will learn metric measurement and application of maths in fun way

### Looking for Class I-V Tuition ?

Learn from Best Tutors on UrbanPro.

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you

X

### Looking for Class I-V Tuition Classes?

The best tutors for Class I-V Tuition Classes are on UrbanPro

• Select the best Tutor
• Book & Attend a Free Demo
• Pay and start Learning

### Take Class I-V Tuition with the Best Tutors

The best Tutors for Class I-V Tuition Classes are on UrbanPro