The video tutorial explains the concept of factors and factor pairs, using a number line to find all factor pairs for a given whole number. The example of the number 20 is used to demonstrate the process, identifying factor pairs such as 1 and 20, 2 and 10, and 4 and 5. The tutorial also explains why certain numbers, like 3, are not factors of 20. The lesson concludes by summarizing the factor pairs and factors of 20, emphasizing the method of using a number line to find them.

Why is the number 3 not a factor of 20?

What are the factors for the number 20?