Finding Least Common Multiples

This video tutorial explains how to find the least common multiple (LCM) of two or more numbers. It begins with an introduction to the concept of multiples and clarifies common misconceptions, such as confusing multiples with factors. The tutorial then provides a detailed, step-by-step process to find the LCM of 12 and 15 by listing and comparing their multiples. It further demonstrates finding the LCM of 4, 7, and 12 by checking the multiples of the largest number against the others. The lesson concludes with a summary of the methods taught.

What is the least common multiple (LCM) of two numbers?

• The smallest number that is a multiple of both numbers

• The largest number that is a factor of both numbers

• The smallest number that is a factor of both numbers

• The largest number that is a multiple of both numbers

Which of the following is a multiple of 5?

• 3

• 10

• 12

• 7

What is a common mistake when identifying multiples?

• Confusing multiples with products

• Confusing multiples with factors

• Confusing multiples with sums

• Confusing multiples with differences

What is the purpose of skip counting when finding multiples?

• To find the difference between numbers

• To find the sum of numbers

• To list factors of a number

• To list multiples of a number

What is the first common multiple of 12 and 15?

• 30

• 75

• 45

• 60

How do you find the LCM of two numbers?

• By dividing the larger number by the smaller

• By adding the numbers

• By listing and comparing their multiples

• By subtracting the smaller number from the larger

What is the LCM of 12 and 15?

• 30

• 60

• 75

• 45

When finding the LCM of 4, 7, and 12, why start with the largest number?

• It is the average of the numbers

• It is the easiest to calculate

• It is the maximum amount the multiple could be

• It is the minimum amount the multiple could be

What is the LCM of 4, 7, and 12?

• 84

• 72

• 60

• 48

Which of the following is NOT a step in finding the LCM of multiple numbers?

• Listing multiples of each number

• Finding the smallest common multiple

• Comparing lists of multiples

• Adding all the numbers together