Understanding GCF, LCM, and LCD

This video tutorial teaches students how to find the greatest common factor (GCF), least common multiple (LCM), and least common denominator (LCD). It begins with an introduction to factors, providing examples to illustrate the concept. The tutorial then explains how to determine the GCF by listing factors and identifying the largest common one. Next, it covers the LCM, showing how to list multiples and find the smallest common multiple. Finally, the video demonstrates how to calculate the LCD for fractions by finding the least common multiple of the denominators. The lesson concludes with a recap of the key points covered.

What are the factors of 12?

• 1, 3, 5, 15

• 1, 2, 4, 8, 16

• 1, 2, 3, 4, 6, 12

• 1, 2, 5, 10

Which of the following is a factor of 16?

• 10

• 12

• 8

• 5

Which of the following is not a factor of 12?

• 2

• 3

• 5

• 6

What is the greatest common factor of 6 and 9?

• 1

• 2

• 6

• 3

Which number is the greatest common factor of 8 and 2?

• 1

• 8

• 2

• 4

What is the least common multiple of 10 and 2?

• 20

• 2

• 5

• 10

Which of the following is a multiple of 2?

• 8

• 7

• 5

• 3

What is a common multiple of 3 and 6?

• 15

• 12

• 9

• 6

What is the least common denominator of 2/3 and 1/6?

• 6

• 3

• 9

• 12

Which number is the least common denominator of 3/7 and 2/4?

• 35

• 28

• 21

• 14