MyMaths MyLife

Facts And Formulae:

Highest Common Factor:(H.C.F) or Greatest Common Meaure(G.C.M) :
The H.C.F of two or more than two numbers is the greatest
number that divides each of them exactly.

There are two methods :

i.Factorization method: Express each one of the given numbers as
the product of prime factors. The product of least powers of common
prime factors gives HCF.

Example : Find HCF of 26 * 32*5*74 , 22 *35*52 * 76 ,
2*52 *72
Solution: The prime numbers given common numbers are 2,5,7
Therefore HCF is 22 * 5 *72 .

ii.Division Method : Divide the larger number by smaller one. Now
divide the divisor by remainder. Repeat the process of dividing
preceding number last obtained till zero is obtained as number. The
last divisor is HCF.


Least common multiple[LCM] : The least number which is
divisible by each one of given numbers is LCM.

There are two methods for this:

i.Factorization method : Resolve each one into product of prime
factors. Then LCM is product of highest powers of all factors.

ii.Common division method.