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5 Minute Check Complete on the back of your homework. Tell whether each number is divisible by 2,3,4,5,6,9,10. 1. 80 2. 81 3. 93 4. 324 5. 665 6. 24,681 Slide 2 5 Minute Check Complete on the back of your homework. Tell whether each number is divisible by 2,3,4,5,6,9,10. 1. 80 2, 4, 5, 10 2. 81 3. 93 4. 324 5. 665 6. 24,681 Slide 3 5 Minute Check Complete on the back of your homework. Tell whether each number is divisible by 2,3,4,5,6,9,10. 1. 80 2, 4, 5, 10 2. 81- 3, 9 3. 93 4. 324 5. 665 6. 24,681 Slide 4 5 Minute Check Complete on the back of your homework. Tell whether each number is divisible by 2,3,4,5,6,9,10. 1. 80 2, 4, 5, 10 2. 81- 3, 9 3. 93 3 4. 324 5. 665 6. 24,681 Slide 5 5 Minute Check Complete on the back of your homework. Tell whether each number is divisible by 2,3,4,5,6,9,10. 1. 80 2, 4, 5, 10 2. 81- 3, 9 3. 93 3 4. 324 2, 4 5. 665 6. 24,681 Slide 6 5 Minute Check Complete on the back of your homework. Tell whether each number is divisible by 2,3,4,5,6,9,10. 1. 80 2, 4, 5, 10 2. 81- 3, 9 3. 93 3 4. 324 2, 4 5. 665 - 5 6. 24,681 Slide 7 5 Minute Check Complete on the back of your homework. Tell whether each number is divisible by 2,3,4,5,6,9,10. 1. 80 2, 4, 5, 10 2. 81- 3, 9 3. 93 3 4. 324 2, 4 5. 665 - 5 6. 24,681- 3 Slide 8 Thursday, Aug 21 Review Lesson 2 Prime Factors Slide 9 When two or more numbers are multiplied, each number is called a factor of the product. example - 1 x 7 = 7 The factors of 7 are 1 and 7 1 x 6 = 6 and 2 x 3 = 6 The factors of 6 are 1,2,3,6 Slide 10 Prime Factors A prime number is a number that only has 2 factors. example - 1 x 7 = 7(prime number) The factors of 7 are 1 and 7 1 x 6 = 6 and 2 x 3 = 6 (not a prime number) The factors of 6 are 1,2,3,6 Slide 11 Prime Factors A whole number, greater than 1, that has more than 2 factors is a composite number. example - 1 x 7 = 7(prime number) The factors of 7 are 1 and 7 1 x 6 = 6 and 2 x 3 = 6 (composite number) The factors of 6 are 1,2,3,6 Slide 12 Prime Factors Is 27 a prime or composite number? (Hint- think about the divisibility rules or make a factor rainbow.) Slide 13 Prime Factors Is 27 a prime or composite number? Multiples List 27: 1, 3, 9, 27 27 is a composite number. Slide 14 Prime Factors I s 82 a prime or composite number? Slide 15 Prime Factors I s 82 a prime or composite number? Multiples List 82: 1, 2, 41, 82 82 is a composite number. Slide 16 Prime Factors What is the only prime number that is even? Slide 17 Prime Factors What is the only prime number that is even? 2 Slide 18 Prime Factors Is 47 a prime or composite number? Slide 19 Prime Factors Is 47 a prime or composite number? Multiples List 47: 1, 47 47 is a prime number. Slide 20 Prime Factors Every composite number can be expressed as a product of prime numbers. This is called prime factorization of the number. A factor tree can be used to find the prime factorization of a composite number. Slide 21 Prime Factors In a factor tree we factor out (divide by) prime numbers. We start with the smallest prime number and keep dividing until it is not divisible. What is the smallest prime number? Slide 22 Prime Factors Find the prime factorization of 45. Is 45 divisible by 2? Slide 23 Prime Factors Find the prime factorization of 45. Is 45 divisible by 2? No. Is 45 divisible by 3? Slide 24 Prime Factors Yes, 45 3 = 15 45 / \ 3 x 15 We keep dividing by 3 until it is not divisible. Is 15 divisible by 3? Circle all prime numbers Slide 25 Prime Factors Yes, 15 3 = 5 45 / \ 3 x 15 I / \ 3 x 3 x 5 Since we have all prime numbers, we are done. The prime factorization of 45 is 3 x 3 x 5, or 3 x 5. Slide 26 Prime Factors Find the prime factorization of 54. What do we divide by first ? Slide 27 Prime Factors 54 2 = 27 54 / \ 2 x 27 We keep dividing by 2 until it is not divisible. Is 27 divisible by 2? Slide 28 Prime Factors No, we are done dividing by 2. 54 / \ 2 x 27 What is the next greatest prime number? Slide 29 Prime Factors Is 27 divisible by 3? 54 / \ 2 x 27 Slide 30 Prime Factors Yes, 27 3 = 9 54 / \ 2 x 27 I / \ 2 x 3 x 9 Is 9 divisible by 3? Slide 31 Prime Factors Yes, 9 3 = 3 54 / \ 2 x 27 I / \ 2 x 3 x 9 I I / \ 2 x 3 x 3 x 3 Once we have all prime numbers, we are done. The prime factorization of 54 is 2 X 3 X 3 X 3, or 2 X 3. Slide 32 Prime Factors Find the prime factorization of 28. Do this on your own. Slide 33 Prime Factors Find the prime factorization of 28. 28 / \ 2 x 14 I / \ 2 x 2 x 7 The prime factorization of 28 is 2 x 2 x 7, or 2 x 7 Slide 34 Prime Factors Find the prime factorization of 30. Do this on your own. Slide 35 Prime Factors Find the prime factorization of 30. 30 / \ 2 x 15 I / \ 2 x 3 x 5 The prime factorization of 30 is 2 x 3 x 5 Slide 36 Prime Factors Find the prime factorization of 43. Do this on your own. Slide 37 Prime Factors Find the prime factorization of 43. 43 is a prime number. Slide 38 Prime Factors Find the prime factorization of 104. Do this on your own. Slide 39 Prime Factors Find the prime factorization of 104. 104 / \ 2 x 52 I / \ 2 x 2 x 26 I I / \ 2 x 2 x 2 x 13 The prime factorization of 104 is 2 x 2 x 2 x 13, or 2 x 13 Slide 40 Prime Factors Find the prime factorization of 128. Do this on your own. Slide 41 Prime Factors Find the prime factorization of 128. 128 / \ 2 x 64 I / \ 2 x 2 x 32 I I / \ 2 x 2 x 2 x 16 I I l / \ 2 x 2 x 2 x 2 x 8 I I l l / \ 2 x 2 x 2 x 2 x 2 x 4 I I l l l / \ 2 x 2 x 2 x 2 x 2 x 2 x 2 Slide 42 Prime Factors Slide 43 Agenda Notes Homework Homework Practice R.2 Due Friday, Aug 22