How to find the Lowest Common Multiple (LCM) #6

The video tutorial explains how to find the Least Common Multiple (LCM) of numbers using two methods: listing multiples and prime factorization. It provides examples for both methods, demonstrating the process step-by-step. The tutorial emphasizes the importance of finding the smallest common multiple and warns against shortcuts that may lead to incorrect results. It encourages practice to understand the concept better.

What is the Least Common Multiple (LCM) of a set of numbers?

• The largest number that divides all the numbers

• The difference between the largest and smallest numbers

• The smallest number that is a multiple of all the numbers

• The sum of all the numbers

When finding the LCM of 6 and 10, which number is the smallest common multiple?

• 12

• 18

• 30

• 60

Why is multiplying the numbers not always the best method to find the LCM?

• It always gives the largest common multiple

• It is too complicated

• It only works for prime numbers

• It may not give the least common multiple

What is the LCM of 5 and 8 using the listing method?

• 30

• 50

• 20

• 40

How do you use prime factors to find the LCM of two numbers?

• Divide the largest prime factor by the smallest

• Subtract the smaller prime factors from the larger ones

• Multiply all the prime factors, counting common ones only once

• Add all the prime factors together

What is the LCM of 28 and 42 using their prime factors?

• 126

• 112

• 84

• 56

What is the LCM of 132 and 420 using the prime factor method?

• 1,320

• 2,640

• 4,620

• 5,040