Finding GCF and LCM of Numbers

This video tutorial by Mr. Jay provides a comprehensive guide to understanding and calculating the Greatest Common Factor (GCF) and Least Common Multiple (LCM). It covers basic concepts, different strategies, and examples involving two and three numbers. The video explains how to find the GCF by listing factors and using prime factorization, and similarly, how to find the LCM by listing multiples and using prime factorization. The tutorial is designed to help students grasp these fundamental math concepts through clear explanations and practical examples.

What is the greatest common factor (GCF) of 12 and 18?

• 9

• 2

• 6

• 3

Which of the following is a common factor of both 16 and 24?

• 12

• 10

• 8

• 5

What is the GCF of 15 and 35?

• 15

• 7

• 5

• 3

Using prime factorization, what is the GCF of 63 and 84?

• 7

• 9

• 21

• 42

What is the GCF of 48 and 72 using prime factorization?

• 36

• 24

• 16

• 12

What is the GCF of the numbers 27, 9, and 18?

• 12

• 3

• 6

• 9

Using prime factorization, what is the GCF of 54, 36, and 90?

• 27

• 9

• 12

• 18

What is the least common multiple (LCM) of 6 and 15?

• 15

• 30

• 60

• 45

What is the LCM of 9 and 12?

• 36

• 48

• 24

• 18

Using prime factorization, what is the LCM of 21, 28, and 32?

• 672

• 168

• 504

• 336