Learning how to find the prime factorization of a number is important when we start learning about fractions. This is especially important when we start reducing fractions. Here are some vocabulary words that will help you with this lesson:

**Factor**: A number that divides evenly into another number (Example: 3 is a factor of 12 because \(12 \div 3\) is a whole number).**Prime Number**: Any number where the only factors are 1 and itself (Example: 11 is a prime number. There is no other number other than 1 and 11 you can divide it by that will give you a whole number).

The first video will explain more about primes and how to determine if a number is prime.

Video Source (05:52 mins) | Transcript

Once we know what prime numbers are, we learn that each number is made up of smaller prime numbers. Breaking a number into the primes that make it is called its prime factorization. Every number has a prime factorization. For prime numbers, their only factors are themselves and 1. This video will show how to find the prime factorization of a number and work through a couple of examples.

Video Source (06:44 mins) | Transcript

It’s helpful to memorize some of the prime numbers, which will make it easier to find prime factorization in future problems. Use this chart to memorize the primes up to 20. Be familiar with the prime numbers up to 100.

## Additional Resources

- Khan Academy: Prime Numbers (08:12 mins, Transcript)
- Khan Academy: Prime Factorization (04:08 mins, Transcript)
- Khan Academy: Prime Factorization Examples (03:48 mins, Transcript)

### Practice Problems

**Find the prime factorization of the following numbers:**

- 21 (Solution
- 13 (Solution
- 30 (Video Solution
- 12 (Solution
- 54 (Solution
- 250 (Video Solution

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