COMMON FACTORS What Is a Factor? 5 x 4 = 20 → 5 and 4 are FACTORS Factors are two numbers multiplied together to get a product (an answer to a multiplication problem). Example: Factors of 18 → 1, 2, 3, 6, 9, 18 (1 x 18 =18, 2 x 9 =18, 3 x 6 = 18, 6 x 3 = 18,9 x 2 =18, 18 x 1 = 18) Factors of 12 → 1, 2, 3, 4, 6, 12 (1 x 12 = 12, 2 x 6 = 12, 3 x 4 =12, 4 x 3 =12, 6 x 2 = 12, 12 x 1 = 12) A common factor is a factor of two or more numbers. • Two numbers may have more than ONE common factor. Factors of 18 → 1, 2, 3, 6, 9, 18 Factors of 12 → 1, 2, 3, 4, 6, 12 The common factors of 18 and 12 are 1, 2, 3, and 6.
Finding the greatest common factor of two numbers: The greatest common factor of two numbers is the LARGEST number that two or more numbers have in common. Factors of 18 → 1, 2, 3, 6, 9, 18 Factors of 12 → 1, 2, 3, 4, 6, 12 The GREATEST common factor of 18 and 12 is 6.