Prime Factorization is the process of breaking down a number into a product of prime numbers (numbers that have no factors other than 1 and themselves). A helpful way to find these prime factors is by using factor trees.
Steps for Prime Factorization
- Start with the Number: Choose a number you want to factor.
- Choose Factors: Think of two numbers that multiply to get that number. Write the number at the top, then draw two branches for the factors.
- Repeat Until All Factors are Prime: For each composite (non-prime) factor, keep breaking it down into smaller factors. Stop when all branches lead to prime numbers.
- List the Prime Factors: Once all factors are prime, list them.
- Combine Like Factors with Exponents: Group any repeating prime factors using exponents to simplify the answer.
Example 1: Prime Factorization of 180
- Start: Write 180.
- First Split: Choose factors like and .
- Continue Factoring:
- is already prime.
- Break down into and .
- is prime.
- Break 30 down into 1 and .
- Break 15 into and , which are both prime.
- List Prime Factors: , , 3, , and .
- Combine with Exponents: 180=2^2⋅3^2⋅5.
Example 2: Prime Factorization of 210
- Start: Write .
- First Split: Choose factors like and 105.
- Continue Factoring:
- is prime.
- Break 105 into and 21.
- 5 is prime.
- Break 21 into and , both prime.
- List Prime Factors: 2, 3, 5, and .
- Final Answer: 210=2⋅3⋅5⋅7