Understanding GCF and LCM Concepts

This video tutorial explains how to find the least common multiple (LCM) and greatest common factor (GCF) of the numbers 5, 6, and 15 using factor trees. It begins with factoring each number into its prime components, then creating a factor chart. The video demonstrates calculating the LCM by multiplying the highest power of each prime factor and finding the GCF by identifying common factors. The tutorial concludes with a summary and a call to action for viewers to subscribe for more educational content.

What is the purpose of using factor trees in this video?

• To identify the largest number

• To calculate the average of numbers

• To determine the prime factors of numbers

• To find the sum of numbers

Which of the following numbers is a prime factor of 5?

• 6

• 2

• 3

• 5

What are the prime factors of 6?

• 2 and 3

• 3 and 5

• 2 and 5

• 5 and 6

How is the factor chart used in this video?

• To list prime factors of each number

• To subtract numbers

• To divide numbers

• To add numbers

What is the first step in calculating the LCM using the factor chart?

• Divide by the largest factor

• Multiply all the factors together

• Subtract the smallest factor

• Add all the numbers

Which factors are used only once when calculating the LCM?

• Only the smallest factor

• Only the largest factor

• All factors

• Factors that appear more than once

What is the LCM of 5, 6, and 15?

• 15

• 90

• 30

• 60

What is required to find the GCF of three numbers?

• All factors must be the same

• At least one triplet of factors

• At least one pair of factors

• No common factors

What is the GCF of 5, 6, and 15?

• 5

• 6

• 1

• 15

Why is the GCF of 5, 6, and 15 equal to 1?

• Because they have a common factor of 5

• Because all numbers are prime

• Because there are no common factors

• Because they have a common factor of 6