Understanding Factors and Highest Common Factors

The video tutorial explains the concept of factors and highest common factors. It begins by defining factors as numbers that multiply to form another number. The tutorial explores the factors of 20, 12, 16, and 30, and demonstrates how to find common factors between pairs of numbers, such as 20 and 12, 12 and 16, and 20 and 30. The highest common factor is identified for each pair. The video concludes with a practice problem for viewers to find the highest common factor of 12 and 18.

Which of the following is NOT a factor of 20?

• 10

• 5

• 2

• 9

What is the highest common factor of 20 and 12?

• 3

• 4

• 6

• 2

What is the highest common factor of 12 and 16?

• 8

• 4

• 3

• 2

Which of these numbers is a factor of 30 but not a factor of 20?

• 10

• 6

• 5

• 2

What is the highest common factor of 20 and 30?

• 20

• 10

• 15

• 5