In this lesson, we learn about factors and prime numbers. Factors are the numbers that are multiplied together to get a product. We can easily find the factors of a number by listing all the numbers that go into it. A prime number is a number that has exactly two factors, 1 and itself. We can determine if a number is prime by checking if it is divisible by any number other than 1 and itself. The lesson ends with a list of odd numbers up to 105 and how to determine which ones are prime using the divisibility tests.
Defines factors and prime numbers, and how to determine if a number is prime or not.
More free YouTube videos by Julie Harland are organized at http://yourmathgal.com