GCF, LCM, Factor Trees

Front

What is the definition of GCF (Greatest Common Factor)?

Back

The GCF of two or more numbers is the largest number that divides all of them without leaving a remainder.

Front

What is the definition of LCM (Least Common Multiple)?

Back

The LCM of two or more numbers is the smallest number that is a multiple of all of them.

Front

List the factors of 12.

Back

1, 2, 3, 4, 6, 12

Front

What is the prime factorization of 30?

Back

2 × 3 × 5

Front

How do you find the GCF of 24 and 36?

Back

List the factors: 24 (1, 2, 3, 4, 6, 8, 12, 24) and 36 (1, 2, 3, 4, 6, 9, 12, 18, 36). The GCF is 12.

Front

How do you find the LCM of 4 and 5?

Back

List the multiples: 4 (4, 8, 12, 16, 20, ...) and 5 (5, 10, 15, 20, ...). The LCM is 20.

Front

What is a factor tree?

Back

A factor tree is a diagram used to break down a number into its prime factors.

Front

Use a factor tree to find the prime factorization of 60.

Back

60 = 2 × 2 × 3 × 5 or 2^2 × 3 × 5.

Front

What are the prime factors of 81?

Back

3 × 3 × 3 × 3 or 3^4.

Front

What is the GCF of 15 and 25?

Back

The GCF is 5.