These lessons, with videos, examples and step-by-step solutions, explain how to find the greatest common divisor (GCD) or greatest common factor (GCF) using the definition, factor tree, repeated division, ladder method, Euclidean Algorithm.

**Related Pages**

Finding Greatest Common Factor

Least Common Multiple - LCM

More Arithmetic Lessons

Free Math Worksheets

The following diagrams show how to find the greatest common divisor (GCD). Scroll down the page for more examples and solutions on finding the greatest common divisor.

**Greatest Common Divisors (GCDs)**

Learn the definition of the “greatest common divisor” and solve three examples.

**Examples:**

- Find gcd(12, 15)
- Find gcd(9, 10)
- Find gcd(9, 12, 21)

**How to find the Greatest Common Divisor, using the factor tree method?**

**Examples:**

- Find the GCD of 72 and 8.
- Find the GCD of 76 and 52.

**Use “repeated division”, “double division” or the “ladder method” to find the GCF or GCD of two numbers**

**Example:**

Find the GCD of 24 and 60

**How to Find the Greatest Common Divisor by Using the Euclidean Algorithm?**

**Examples:**

Find GCD(10, 45)

Find GCD(1701, 3768)

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