**Method 1:**

List the factors of each number.

Factors of 12: 2, 3, 4, 6, 12

Factors of 30: 2, 3, 5, 6, 10, 15, 30

Identify the greatest common factor.

The greatest common factor of 12 and 30 is 6.

**Method 2:**

Write the prime factorization of each number.

12 = 3 × 2 × 2.

30 = 3 × 2 × 5.

The GCF is the product of the common prime factors in each number.

GCF = 3 × 2.

The greatest common factor of 12 and 30 is 6.

The greatest common factor of 12 and 30 is 6.

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