Finding the Least Common Multiple

The video tutorial covers the concept of the least common multiple (LCM), starting with an introduction and learning target. It explains how to find the LCM using two methods: listing multiples and prime factorization. The tutorial includes examples with two and three numbers, and a real-life application involving traffic lights. Practice problems are provided for reinforcement.

What does the 'C' in LCM stand for?

• Constant

• Complex

• Calculated

• Common

When listing multiples to find the LCM, what is the first multiple of any number?

• Zero

• The number itself

• Ten

• One

In the listing multiples method, what is the LCM of 4 and 6?

• 8

• 10

• 12

• 14

What is the first step in finding the LCM using prime factorization?

• Add the numbers

• List all factors

• Create factor trees

• Multiply the numbers

Using prime factorization, what is the LCM of 16 and 20?

• 40

• 80

• 100

• 60

When finding the LCM of three numbers, why might you prefer the factor tree method?

• It's faster

• It simplifies calculations

• It uses less paper

• It avoids large numbers

What is the LCM of 4, 15, and 18 using the factor tree method?

• 150

• 120

• 180

• 210

In the traffic light example, how often do both lights change at the same time?

• Every 120 seconds

• Every 150 seconds

• Every 90 seconds

• Every 60 seconds

How many minutes is 120 seconds?

• 1 minute

• 1.5 minutes

• 2 minutes

• 2.5 minutes

If the second traffic light changes every 45 seconds, how often will both lights change together?

• Every 90 seconds

• Every 120 seconds

• Every 150 seconds

• Every 60 seconds