What is LCF & HCF ? Tricks


1. HCF (Highest Common Factor), Also called: GCD (Greatest Common Divisor)


Definition: HCF is the greatest number that divides two or more given numbers exactly. HCF āĻŦ⧁āϞāĻŋāϞ⧇ āĻĻ⧁āϟāĻž āĻŦāĻž āϤāϤ⧋āϧāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻžāĻ• āϏāĻŽā§āĻĒā§‚ā§°ā§āĻŖāĻ­āĻžā§ąā§‡ āĻ­āĻžāĻ— āϕ⧰āĻŋāĻŦ āĻĒā§°āĻž āĻ¸ā§°ā§āĻŦāĻžāϧāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻžāĻ• āĻŦ⧁āϜāĻžāϝāĻŧāĨ¤


Ex / āωāĻĻāĻžāĻšā§°āĻŖ: Find HCF of 12 and 18.


Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 18: 1, 2, 3, 6, 9, 18


Common factors: 1, 2, 3, 6
HCF = 6


2. LCM (Least Common Multiple)


Definition: LCM is the smallest number that is a multiple of two or more given numbers. LCM āĻŦ⧁āϞāĻŋāϞ⧇ āĻĻ⧁āϟāĻž āĻŦāĻž āϤāϤ⧋āϧāĻŋāĻ• āϏāĻ‚āĻ–ā§āϝāĻžā§° āĻ¸ā§°ā§āĻŦāύāĻŋāĻŽā§āύ āϏāĻžāϧāĻžā§°āĻŖ āϗ⧁āĻŖāĻŋāϤāĻ•āĻ• āĻŦ⧁āϜāĻžāϝāĻŧāĨ¤


Ex / āωāĻĻāĻžāĻšā§°āĻŖ: Find LCM of 12 and 18.


Write prime factors


12 = 2 × 2 × 3 = 2²×3
18 = 2 × 3 × 3 = 2×3²


Highest power of each prime: 2², 3²


LCM = 36


Key Difference 



  • HCF: Biggest common divisor. HCF: āĻ¸ā§°ā§āĻŦāĻžāϧāĻŋāĻ• āϏāĻžāϧāĻžā§°āĻŖ āϗ⧁āĻŖāύ⧀āϝāĻŧāĻ•

  • LCM: Smallest common multiple. LCM: āĻ¸ā§°ā§āĻŦāύāĻŋāĻŽā§āύ āϏāĻžāϧāĻžā§°āĻŖ āϗ⧁āĻŖāĻŋāϤāĻ•


What is LCF & HCF ? Tricks