Greatest Common Factor and Prime Factors

The video tutorial explains how to find the greatest common factor (GCF) of 12 and 15 using a factor tree method. It begins by breaking down each number into its prime factors, then organizes these factors into a chart. The GCF is identified as the common prime factor present in both numbers, which is 3. The tutorial provides a step-by-step approach to ensure understanding of the process.

What is the first step in finding the greatest common factor of 12 and 15 using a factor tree?

• List all factors of 12 and 15

• Multiply 12 and 15

• Break down 12 into its prime factors

• Divide both numbers by 2

Which of the following is a prime factor of 15?

• 4

• 6

• 3

• 2

What is the purpose of creating a chart in the factor tree method?

• To divide the numbers

• To multiply the numbers

• To compare prime factors of both numbers

• To list all numbers

Which column in the chart indicates the greatest common factor of 12 and 15?

• The column with the number 6

• The column with the number 3

• The column with the number 5

• The column with the number 2

What is the greatest common factor of 12 and 15?

• 2

• 3

• 5

• 6