5 Minute Check

1. 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

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

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

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

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

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

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

8. Thursday, Aug 21 Review Lesson 2 Prime Factors

9. Prime Factors 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

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

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

12. Prime Factors Is 27 a prime or composite number? (Hint- think about the divisibility rules or make a factor rainbow.)

13. Prime Factors Is 27 a prime or composite number? Multiples List 27: 1, 3, 9, 27 27 is a composite number.

14. Prime Factors Is 82 a prime or composite number?

15. Prime Factors Is 82 a prime or composite number? Multiples List 82: 1, 2, 41, 82 82 is a composite number.

16. Prime Factors What is the only prime number that is even?

17. Prime Factors What is the only prime number that is even? 2

18. Prime Factors Is 47 a prime or composite number?

19. Prime Factors Is 47 a prime or composite number? Multiples List 47: 1, 47 47 is a prime number.

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.

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?

22. Prime Factors Find the prime factorization of 45. Is 45 divisible by 2?

23. Prime Factors Find the prime factorization of 45. Is 45 divisible by 2? No. Is 45 divisible by 3?

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

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 3² x 5.

26. Prime Factors Find the prime factorization of 54. What do we divide by first?

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?

28. Prime Factors No, we are done dividing by 2. 54 / \ 2 x 27 What is the next greatest prime number?

29. Prime Factors Is 27 divisible by 3? 54 / \ 2 x 27

30. Prime Factors Yes, 27 ÷ 3 = 9 54 / \ 2 x 27 I / \ 2 x 3 x 9 Is 9 divisible by 3?

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 3³.

32. Prime Factors Find the prime factorization of 28. Do this on your own.

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 2² x 7

34. Prime Factors Find the prime factorization of 30. Do this on your own.

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

36. Prime Factors Find the prime factorization of 43. Do this on your own.

37. Prime Factors Find the prime factorization of 43. 43 is a prime number.

38. Prime Factors Find the prime factorization of 104. Do this on your own.

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 2³ x 13

40. Prime Factors Find the prime factorization of 128. Do this on your own.

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 Il / \ 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 ll / \ 2 x 2 x 2 x 2 x 2 x 2 x 2

42. Prime Factors

43. Prime Factors Agenda Notes Homework – Homework Practice R.2 Due Friday, Aug 22