Finding GCF and LCM Concepts

The video tutorial explains how to find the Least Common Multiple (LCM) and Greatest Common Factor (GCF) of the numbers 77, 91, and 143 using a factor tree method. It begins with the prime factorization of each number, then demonstrates how to calculate the LCM by multiplying the prime factors, considering each factor only once if it appears in multiple numbers. The tutorial also covers finding the GCF by identifying common factors across all numbers. 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 finding LCM and GCF?

• To simplify the numbers

• To identify prime factors

• To add the numbers

• To divide the numbers

Which of the following is a prime factor of 77?

• 15

• 7

• 9

• 13

What are the prime factors of 91?

• 7 and 11

• 7 and 13

• 11 and 13

• 11 and 17

How do you find the LCM of multiple numbers?

• Multiply all prime factors, using each factor only once

• Subtract the smallest number from the largest

• Add all the numbers

• Divide the largest number by the smallest

What is the LCM of 77, 91, and 143?

• 91

• 1001

• 143

• 77

Which number is a common factor of 77, 91, and 143?

• 7

• 13

• 1

• 11

What is the GCF of 77, 91, and 143?

• 7

• 11

• 1

• 13

Why can't 7 be the GCF of 77, 91, and 143?

• It is not a factor of 91

• It is not a factor of any number

• It is not a factor of 77

• It is not a factor of 143

What is the significance of the number 1 in finding the GCF?

• It is the smallest number that divides all numbers evenly

• It is the largest prime number

• It is the largest number that divides all numbers evenly

• It is the smallest prime number

What should you do after finding the LCM and GCF?

• Add them together

• Divide them by each other

• Multiply them together

• Share and subscribe for more videos