Finding Greatest Common Factors and Least Common Multiples

The video tutorial covers finding the greatest common factor (GCF) and least common multiple (LCM) of number pairs using the list method. The instructor provides step-by-step examples for each concept, demonstrating how to list factors and multiples to identify common values. The tutorial includes exercises for GCF of 6 and 10, 22 and 99, 30 and 18, and 9 and 16, as well as LCM of 4 and 10, 12 and 8, 25 and 4, and 40 and 12. The video aims to reinforce understanding of these mathematical concepts through practical examples.

What is the first step in finding the greatest common factor or least common multiple according to the video?

• Multiply the numbers together.

• List all the factors of the numbers.

• List all the multiples of the numbers.

• Divide the numbers by each other.

What is the greatest common factor of 6 and 10?

• 3

• 2

• 5

• 1

Tags

CCSS.4.OA.B.4

Which of the following is a common factor of both 22 and 99?

• 22

• 2

• 3

• 11

What is the greatest common factor of 30 and 18?

• 6

• 9

• 3

• 12

What is the greatest common factor of 9 and 16?

• 3

• 9

• 16

• 1

What is the least common multiple of 4 and 10?

• 10

• 40

• 20

• 30

What is the least common multiple of 12 and 8?

• 24

• 16

• 32

• 48

What is the least common multiple of 25 and 4?

• 50

• 75

• 100

• 125

What is the least common multiple of 40 and 12?

• 120

• 140

• 80

• 100

Which method is used in the video to find the least common multiple?

• Division method

• Prime factorization

• List method

• Subtraction method