Finding GCF and LCM through Prime Factorization

In this video, Mr. J explains how to find the greatest common factor (GCF) and least common multiple (LCM) using prime factorization. He demonstrates the process with examples, starting with finding the GCF of 63 and 84, followed by 48 and 72. Then, he moves on to finding the LCM of 15 and 27, and finally 28 and 52. The video emphasizes the efficiency of prime factorization for larger numbers.

What is the main advantage of using prime factorization for finding GCF and LCM?

• It simplifies the process for larger numbers.

• It is the only method available.

• It is faster for smaller numbers.

• It avoids the need for multiplication.

What are the prime factors of 63?

• 1, 63

• 7, 9

• 3, 3, 7

• 3, 21

What is the GCF of 63 and 84?

• 7

• 21

• 63

• 3

Which of the following is a prime factor of 48?

• 24

• 6

• 12

• 2

Tags

CCSS.4.OA.B.4

What is the GCF of 48 and 72?

• 48

• 36

• 24

• 12

What are the prime factors of 15?

• 5, 3, 1

• 15, 1

• 3, 5

• 3, 3, 5

What is the LCM of 15 and 27?

• 45

• 90

• 135

• 270

What is the prime factorization of 28?

• 4, 7

• 2, 7

• 2, 2, 7

• 2, 14

What is the LCM of 28 and 52?

• 208

• 156

• 364

• 104

Which of the following is a prime factor of 52?

• 52

• 26

• 4

• 13

Tags

CCSS.4.OA.B.4