Understanding LCM and GCF

The video tutorial explains how to find the Lowest Common Multiple (LCM) and Greatest Common Factor (GCF) of the numbers 18 and 24 using factor trees. It begins with an introduction to the concepts, followed by creating factor trees for both numbers. The tutorial then demonstrates how to calculate the LCM by multiplying the prime factors, considering common factors only once. Next, it explains how to find the GCF by identifying common prime factors. The video concludes with a call to action for viewers to subscribe for more math and science content.

What is the purpose of using a factor tree in this video?

• To find the sum of numbers

• To identify prime factors

• To divide numbers

• To calculate the square root

Which of the following is a prime factor of 18?

• 4

• 5

• 2

• 6

What are the prime factors of 18?

• 2, 3, 3

• 2, 2, 3

• 3, 3, 3

• 2, 2, 2

Which of the following is a prime factor of 24?

• 5

• 9

• 7

• 2

What are the prime factors of 24?

• 2, 2, 2, 3

• 2, 2, 3, 3

• 3, 3, 3, 3

• 2, 3, 3, 3

How do you determine the LCM of two numbers using their prime factors?

• Subtract all prime factors

• Multiply all prime factors, using common ones only once

• Add all prime factors

• Divide all prime factors

What is the LCM of 18 and 24?

• 36

• 54

• 72

• 48

How do you determine the GCF of two numbers using their prime factors?

• Subtract all common prime factors

• Divide all common prime factors

• Multiply all common prime factors

• Add all common prime factors

What is the GCF of 18 and 24?

• 10

• 8

• 6

• 4

Which prime numbers are common in both 18 and 24?

• 3 and 5

• 3 and 7

• 2 and 5

• 2 and 3