Understanding LCM through Factor Trees

This video tutorial explains how to find the least common multiple (LCM) of 16 and 20 using a factor tree method. It begins with creating factor trees for both numbers, identifying their prime factors. Then, a chart is drawn to list the multiples of 16 and 20, which helps in reducing mistakes. The video demonstrates how to use the chart to find the LCM by multiplying the prime numbers together, resulting in an LCM of 80. The tutorial concludes with a reminder to subscribe for more math and science videos.

What is the purpose of finding the Least Common Multiple (LCM)?

• To find the average of two numbers.

• To find the largest number that divides two or more numbers.

• To find the smallest number that is a multiple of two or more numbers.

• To find the difference between two numbers.

Which of the following is a prime factor of 16?

• 3

• 2

• 5

• 7

What is the final prime factorization of 16?

• 2 x 3 x 3

• 2 x 2 x 2 x 2

• 2 x 2 x 4

• 4 x 4

Which of the following is a prime factor of 20?

• 9

• 5

• 3

• 7

What is the final prime factorization of 20?

• 4 x 5

• 2 x 5 x 5

• 2 x 3 x 5

• 2 x 2 x 5

How do you determine which prime factors to use when calculating the LCM?

• Use the lowest power of each prime factor that appears in either number.

• Use the highest power of each prime factor that appears in either number.

• Use only the prime factors that appear in both numbers.

• Use all prime factors from both numbers.

What is the LCM of 16 and 20?

• 70

• 60

• 90

• 80

Which step is crucial in ensuring the correct calculation of the LCM?

• Subtracting the smallest prime factor.

• Multiplying the highest power of each prime factor.

• Dividing the largest prime factor by the smallest.

• Adding all the prime factors together.