🎯 About GCD/HCF Calculator

The Greatest Common Divisor (GCD), also known as the Highest Common Factor (HCF), is the largest positive integer that divides all given numbers without a remainder.

Our calculator finds the GCD for 2 to 5 numbers using three different methods: Euclidean Algorithm, Prime Factorization, and Listing Factors.

📝 How to Use

  • Choose how many numbers (2 to 5)
  • Enter your numbers in the input fields
  • Click "Calculate GCD"
  • View results with three different solution methods
  • See practical applications and properties

🔍 Calculation Methods

Method 1: Euclidean Algorithm (Most Efficient)

  • Divide the larger number by the smaller
  • Replace larger with smaller, smaller with remainder
  • Repeat until remainder is 0
  • Last non-zero remainder is the GCD

Method 2: Prime Factorization

  • Break each number into prime factors
  • Find common prime factors
  • Take the lowest power of each common prime
  • Multiply them together

Method 3: Listing Factors

  • List all factors of each number
  • Find common factors
  • The largest common factor is the GCD

💡 Common Uses

  • Simplifying Fractions: Divide numerator and denominator by GCD
  • Problem Solving: Finding largest equal groups
  • Tiling Problems: Largest tile size that fits perfectly
  • Cryptography: Essential in RSA encryption
  • Music Theory: Finding common time signatures

📚 Examples

2 Numbers:

  • GCD(12, 18) = 6
  • GCD(24, 36) = 12
  • GCD(15, 25) = 5

3 Numbers:

  • GCD(12, 18, 24) = 6
  • GCD(20, 30, 40) = 10

Real-World Example:

You have 24 apples and 36 oranges. What's the largest number of identical fruit baskets you can make?
Answer: GCD(24, 36) = 12 baskets (each with 2 apples and 3 oranges)

✨ Key Features

  • Calculate GCD for 2-5 numbers
  • Three different solution methods
  • Step-by-step detailed explanations
  • Shows GCD × LCM relationship
  • Fraction simplification examples
  • Visual factor highlighting
  • Educational and practical