Understanding Least Common Multiples

In this video, Mr. J explains how to find the least common multiple (LCM) of three numbers: 12, 15, and 30. The video is part two of a series, and viewers are encouraged to watch part one first. Mr. J demonstrates how to calculate the first five multiples of each number and then identifies the LCM, which is 60. He also discusses the concept of common multiples being infinite and encourages viewers to extend their lists to find more common multiples. The video concludes with a summary of the process and a reminder of the endless nature of multiples.

What is the main topic covered in this video?

• Finding the least common multiple

• Finding the greatest common divisor

• Understanding fractions

• Solving quadratic equations

What is the first multiple of 12?

• 24

• 36

• 12

• 48

Tags

CCSS.4.OA.B.4

Which of the following is a multiple of 12?

• 55

• 60

• 45

• 50

What is the second multiple of 15?

• 30

• 15

• 45

• 60

Tags

CCSS.4.OA.B.4

Which number is not a multiple of 15?

• 75

• 45

• 50

• 60

What is the third multiple of 30?

• 120

• 150

• 60

• 90

Tags

CCSS.4.OA.B.4

Which of these is a multiple of 30?

• 100

• 90

• 80

• 70

What is the least common multiple of 12, 15, and 30?

• 30

• 45

• 60

• 75

Why are common multiples considered infinite?

• Because they can be extended indefinitely

• Because they repeat every 10 numbers

• Because they are only found in even numbers

• Because they are limited to the first five multiples

What is a key takeaway about multiples from this video?

• Multiples are endless

• Multiples are finite

• Multiples are only for odd numbers

• Multiples are only for even numbers