LCM & HCF YouTube Lecture Handouts

Doorsteptutor material for GRE is prepared by world's top subject experts: get questions, notes, tests, video lectures and more- for all subjects of GRE.

Get video tutorial on: Examrace YouTube Channel

HCF and LCM - 3 Speed Tricks & 10 Typical Word Problems

LCM & HCF Story with Tree & Circles

Mayank explains the following two key concepts to quickly and easily identify and solve all HCF and LCM problems - 1. Quickly find HCF and LCM using 3 simple tricks in this video. 2. To detect HCF and LCM word problems, use the following keywords: LCM 1. Minimum number of days, rounds etc. 2. Least amount of time, things etc. 3. Smallest number, length, amount of time etc. HCF 1. Maximum (possible) number of days, things etc. 2. Longest (possible) size, length, amount of time etc.

Our Journey

  • Factors
    • Prime Factors
  • Multiples
  • Factors and Multiples
  • Highest Common Factor
    • Common Factors
  • Least Common Multiple
    • Common Multiples

Understanding Factors

Prime Factors

  • Factors which are prime (numbers) are called prime factors

Understanding Multiples

Factors and Multiples

  • Factors can (completely) divide the number

< Number

  • Multiples are (completely) divisible by the number.

> Number

Factorization Using Tree of Factors

Factorization Using Tree of Factors Image

Tree of Factors- 24

Common Factors of 32 and 24

Finding Common Factors (HCF) Using Grouping

Common Multiples of 32 and 24

32 … 32, 64, 96, 128, 160,192, 224, …

24 … 24, 48, 72, 96, 120, 144,168, 192, …

Least Common Multiple - LCM

Lowest common Factor – LCM

Highest Common Multiple - HCH

HCF and LCM Combining the Two Steps

Other Names of HCF

  • Greatest Common Factor - GCF
  • Greatest Common Divisor - GCD

Why Prime Factors?

Developed by: