Home › concepts › hcf and lcm

HCF and LCM Explained

HCF (Highest Common Factor) and LCM (Lowest Common Multiple) are fundamental concepts in number theory. They are used to simplify fractions, find common de

✓ 100% Free ✓ No Login Needed ✓ NCERT / CBSE Aligned ✓ Download as PDF

TL;DR: HCF (Highest Common Factor) and LCM (Lowest Common Multiple) are fundamental concepts in number theory. They are used to simplify fractions, find comm…

Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated Jul 23, 2026

🤖 Stuck on any question? Ask Syllab's free AI Tutor for a step-by-step explanation — instant, unlimited, no login.

HCF and LCM: HCF (Highest Common Factor) and LCM (Lowest Common Multiple) are fundamental concepts in number theory. They are used to simplify fractions, find common de

HCF and LCM Explained Simply

HCF (Highest Common Factor) and LCM (Lowest Common Multiple) are fundamental concepts in number theory. They are used to simplify fractions, find common de This is a key Mathematics concept for Class 6-7.

Frequently Asked Questions

What are coprime numbers?

Two numbers are coprime if their HCF is 1, meaning they share no common factors other than 1. For example, 8 and 9 are coprime because HCF(8, 9) equals 1. Any two consecutive integers are always coprime.

Is there a formula for HCF and LCM?

For two numbers a and b: HCF(a, b) times LCM(a, b) equals a times b. The Euclidean algorithm efficiently finds HCF using repeated division. For multiple numbers, apply the formula pairwise.

Can HCF be larger than LCM?

No, HCF is always less than or equal to LCM. HCF is a common divisor (at most the smaller number) while LCM is a common multiple (at least the larger number). They are equal only when the numbers are the same.

Related Mathematics Concepts

  • Pythagoras Theorem Explained
  • Quadratic Equations Explained
  • Trigonometry: Ratios and Identities Explained
  • Probability Explained
  • Polynomials Explained
  • Linear Equations in Two Variables Explained

Browse all concepts →

Explore:

  • Syllabus
  • Practice
  • Mock Tests
  • NCERT Solutions
  • Coding
  • GK Quiz
  • Career Predictor
  • AI Tutor
  • Live Quiz
  • Doubt Solver
  • Microlearning
  • Free Alternatives
  • Kids Zone
  • Study Room
  • Calculators
  • Worksheets

Syllab.in — Free learning for Indian students, Class 1–12