CBSE · Class 6-12

Class 7 · Ganita Prakash

Unit 11 · Class 7Ganita Prakash

Finding Common Ground

Highest common factors, lowest common multiples, and applications.

Lessons

4 concepts

1
HCF via Primes
Factorise both; multiply common primes to lowest power. HCF $(12,18)=2\cdot 3=6$ .
2
LCM via Primes
Factorise both; multiply all primes to highest power. LCM $(12,18)=2^2\cdot 3^2=36$ .
3
HCF × LCM Identity
HCF × LCM = product. Verify: $6\cdot 36 = 216 = 12\cdot 18$ .
4
Real-Life Applications
Cyclists returning to start together — LCM. Cutting equal pieces — HCF.

Skills to practise

Skill · medium

Finding Common Ground — Practice