Comments of Prime Factorization of a Number

Example say 36

The prime numbers in 1 to 10 are 2,3,5,and 7. These numbers can solve prime factorization number upto 100.

so

2  | 36

2  | 18

3  |  9 

3  | 3

   |  1

So prime factorization of 36 is  2x2x3x3 = 36. Note prime factorization is also useful in finding HCF (Highest Common Factor)  and LCM  (Least Common Multiple)

COMMENT: In exam it is advisable to give sums less than 100 because if it is greater then 100 say 150 then we will have to use

prime factors greater then 10 and less than 20. So result the children without calculators will not be able to solve the problems.  

In 1 to 10 the prime factors are 2,3,5, and 7. These prime factors can determine prime factors from 1 to 100 ( 10 x 10)

In 1 to 20 the prime factors are 2,3,5, 7 , 11, 13, 17 and 19. These prime factors can determine prime factors from 1 to 400 ( 20 x 20)

In 1 to 30 the prime factors are 2,3,5, 7 , 11, 13, 17 ,19 , 23, 29. These prime factors can determine prime factors from 1 to 900 ( 30 x 30)

If the prime numbers cannot divide a given number then that number is a prime number.