1. Even Numbers – Any number that can be divided by 2
Odd Numbers – Any number that cannot be divided by 2

2. ODD OR EVEN. 1. Write O for odd and E for even 2
ODD OR EVEN? 1. Write O for odd and E for even 2. Find the half of the number ____ ____ ___ ____ ___ ____ ___ _____ ___ ____ ___ ____

4. WHAT NUMBERS ARE PRIME?
Let’s look at a number grid from 1 to 100 and see how they were discovered.

5. Take out the number 1 because it is a special number
HERE’S HOW YOU DO IT 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
100
Take out the number 1 because it is a special number

6. Take out the number 1 because it is a special number
HERE’S HOW YOU DO IT 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
100
Take out the number 1 because it is a special number

7. Take out numbers that have a composite factor of 2
HERE’S HOW YOU DO IT 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
100
Take out numbers that have a composite factor of 2

8. HERE’S HOW YOU DO IT 2 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99
Take out numbers that have a composite factor of 2
Extra help: Even numbers different from 2.

9. Take out numbers that have a composite factor of 3
HERE’S HOW YOU DO IT 2 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99
Take out numbers that have a composite factor of 3

10. Take out numbers that have a composite factor of 3
HERE’S HOW YOU DO IT 2 3 5 7 11 13 17 19 23 25 29 31 35 37 41 43 47 49 53 55 59 61 65 67 71 73 77 79 83 85 89 91 95 97
Take out numbers that have a composite factor of 3

11. Here’s How You Do It 2 3 5 7 11 13 17 19 23 25 29 31 35 37 41 43 47 49 53 55 59 61 65 67 71 73 77 79 83 85 89 91 95 97
Take out numbers that have a composite factor of 5

12. Take out numbers that have a composite factor of 5
HERE’S HOW YOU DO IT 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 49 53 59 61 67 71 73 77 79 83 89 91 97
Take out numbers that have a composite factor of 5

13. Here’s How You Do It 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 49 53 59 61 67 71 73 77 79 83 89 91 97
Take out numbers that have a composite factor of 7

14. Take out numbers that have a composite factor of 7
The PRIME Numbers! 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
Take out numbers that have a composite factor of 7

15. How do we know numbers are prime?

16. A prime number cannot be divided by anything other than 1 and itself.
That’s It!
A prime number cannot be divided by anything other than 1 and itself.
These are numbers that have only two factors – themselves and one.
An example of Prime Numbers would be…
1,3 (3 3) (3 1) (3 3)

17. How do we know numbers are composite?

18. That’s It! Numbers that have more than two factors . One is included
An example of composite numbers would be:
1,12 2,6 3,4
(1*12) (2*6) (3*4)

19. PRIME OR COMPOSITE?

20. 96

21. Composite Number
96 = 1,96 2,38 3, ,24 6,16 8,12,

22. 15

23. Composite Number
15= 1,3,5,15

24. 47

25. Prime Number
47= 1, 47

26. 93

27. Composite Number
93=
1,93 3,31

28. 54

29. Composite Number
54 =
1, , ,18 6,9

30. 57

31. Composite Number
57=
1, ,19

32. 19

33. Prime Number
19=
1,19

34. Factors are the numbers you multiply together to get a product.
For example, the product 24 has several factors.
24 = 1 x 24
24 = 2 x 12
24 = 3 x 8
24 = 4 x 6
SO, the factors are 1, 2, 3, 4, 6, 8, 12, 24

35. FINDING FACTORS Start with 1 x the number. Try 2, 3, 4, etc.
When you repeat your factors, cross out the repeat - you’re done at this point.
If you get doubles (such as 4 x 4), then you’re done. Repeats or doubles let you know you’re done.

36. What are the factors of 16? The factors of 16 are 1,2,4,8,16 1 x 16
3 is not a factor, so cross it out
4 x 4
doubles = done
The factors of 16 are 1,2,4,8,16

37. What are the factors of 18?

38. What are the factors of 18? The factors are 1,2,3,6,9,18 1 x 18 2 x 9
Repeat! Cross it out! We’re done!
6 x 3
The factors are 1,2,3,6,9,18

39. Find all the factors of each number
Find all the factors of each number. List them in order from least to greatest.
25 ______. _______, _______
27 _____, ______, _______,_______
12 ______, ______, _______, _______, _______, _______.
15 _______, _______, _______ ,_______.
3 _______, ________.
18. ______, _______, ________, _______, _______, _______

40. How to find Prime Factors?
Step 1 – Start with a composite number. 48
Step 2 – Write down a multiplication that equals
this number or any pair of factors of this number.
6 x 8 = 48

41. How to Do Prime Factorization Using a Factor Tree
Step 3 – Find factors of the numbers (factor ) you
got in step 2. 48
6 x 8
2 x 3 x 2 x 4

42. Step 4 – Find factors of these numbers
until all factors are prime numbers. 48
6 x 8
2 x 3 x 2 x 4
2 x 3 x 2 x 2 x 2

43. 2 x 2 x 2 x 2 x 3 Step 6 – Count how many numbers are
the same and write exponents for them.
2 x x 2 x 2 x 3 4
2 x 3 = 48

44. WORKING TOGETHER!!!!!!!

45. Prime factor this number4

46. Prime factor this number4
= 4
2 x 2 2
2 = 4

47. Prime factor this number6

48. Prime factor this number6
= 6
2 x 3

49. Prime factor this number22

50. Prime factor this number22
2 x 11
= 22

51. Prime factor this number12

52. Prime factor this number12
= 12
3 x 4
3 x 2 x 2 = 12
2 x 2 x 3 = 12 2
2 x 3 = 12

53. Prime factor this number21

54. Prime factor this number21
= 21
3 x 7

56. Find the prime factors of these numbers