Finding LCM and GCF Using Factor Trees

This video tutorial from MooMooMath and Science explains how to find the greatest common factor (GCF) and the lowest common multiple (LCM) of the numbers 72, 96, and 120 using factor trees. The instructor demonstrates how to create factor trees for each number, identify prime numbers, and organize them into a chart. The video then guides viewers through the process of finding the GCF by identifying triplets of prime numbers and calculating their product. Similarly, it explains how to find the LCM by multiplying the necessary prime numbers, following specific rules for triplets. The tutorial concludes with a motivational message about kindness.

What is the purpose of using a factor tree in finding the GCF and LCM?

• To divide the numbers

• To add the numbers

• To identify prime factors

• To simplify the numbers

Which of the following is a prime factor of 72?

• 3

• 7

• 5

• 9

How many times does the number 2 appear in the factor tree of 96?

• Three times

• Four times

• Five times

• Six times

What is the next step after creating the factor trees for the numbers?

• Add the numbers

• Divide the numbers

• Multiply the numbers

• Create a chart of prime factors

What is the greatest common factor of 72, 96, and 120?

• 12

• 18

• 30

• 24

When calculating the GCF, what are you looking for among the numbers?

• Pairs of numbers

• Triplets of prime factors

• Quadruplets of numbers

• Single prime factors

What is the rule for selecting numbers when calculating the LCM?

• Select one number from each triplet

• Select only even numbers

• Select all numbers

• Select only odd numbers

Which number is not part of the LCM calculation for 72, 96, and 120?

• 2

• 3

• 5

• 7

What is the lowest common multiple of 72, 96, and 120?

• 720

• 960

• 1680

• 1440

What is the final step in finding the LCM after selecting the necessary numbers?

• Divide the numbers

• Subtract the numbers

• Multiply the numbers

• Add the numbers