Understanding Least Common Multiple (LCM)

This video tutorial explains how to find the least common multiple (LCM) of the numbers 7 and 12 using a factor tree method. It begins with an introduction to the concept of LCM and the use of factor trees. The video then demonstrates creating factor trees for the numbers 7 and 12, followed by building a factor chart. Finally, it shows how to multiply the factors to calculate the LCM, which is 84. The video concludes with a call to action to subscribe for more math and science content.

What is the first step in finding the LCM of two numbers using a factor tree?

• Identify the greatest common divisor

• List all multiples of the numbers

• Break down each number into its prime factors

• Add the numbers together

Why is the number 7 circled immediately in the factor tree?

• Because it is a multiple of 12

• Because it is a composite number

• Because it is a prime number

• Because it is an even number

What are the prime factors of 12 as identified in the video?

• 2, 3, and 6

• 2, 2, and 3

• 3, 4, and 6

• 2, 3, and 7

In the factor chart, what should you do if you have a vertical pair of factors?

• Bring only one of them down

• Ignore them

• Add them together

• Multiply them together

What is the result of multiplying 7, 2, 2, and 3 together?

• 72

• 84

• 56

• 42

What is the least common multiple (LCM) of 7 and 12?

• 96

• 84

• 108

• 72