2. PRIME FACTORIZATION Sally VanCura Cobb 6th Grade Campus GPISD

3. TEKS OBJECTIVE n Objective 6.1 D The student will be able to write prime factorizations using exponents.

4. PURPOSE n The student will be able to draw a factor tree to write a composite number as the product of prime numbers.

5. QUICK REVIEW n A PRIME NUMBER is a number whose only factors are itself and 1. n For example, 41 is a prime number, since its only factors are 1 and itself. n This is the beginning list of prime numbers: 2, 3, 5, 7, 11, ___, ___, ___, ___, ___, ___, n An Answers: 13, 17, 19, 23, 29, 31

6. PRIME FACTORIZATION n A number an be written as a product of all its prime factors. This is called the prime factorization of a number.

7. Write the prime factorization of 24. Strategy: Draw a factor tee, following these steps. Step 1: Draw a factor tree as shown.24 The branches may show any The branches may show any two factors of 24. two factors of 24. 4 6 (**Do not include 1. It is not a prime number.) It is not a prime number.)

8. Step 2: Continue the tree 24 until all branches end in until all branches end in prime numbers. 4 6 prime numbers. 4 6 2 2 2 3 2 2 2 3 Step 3: Write a product, using all the prime numbers at the ends of the branches. at the ends of the branches. SOLUTION: 24 = 2 x 2 x 2 x 3 or 2 3 x 3 Note: When you write prime factors, write them in order from least to greatest Note: When you write prime factors, write them in order from least to greatest

9. ACTIVITY Go to the following website and complete the lesson on prime factorization and complete the lesson on prime factorization http://amby.com/educate/math/2- 1_fact.html http://amby.com/educate/math/2- 1_fact.html