Transcript Prime Numbers Some Simple Tips and Reminders Definitions • Even Numbers – Any number that can be divided by 2 • Odd Numbers –

Prime Numbers
Some Simple Tips and Reminders
Definitions
• Even Numbers – Any number that
can be divided by 2
• Odd Numbers – Any number that
cannot be divided by 2
• Composite Number – An integer that
can be divided by at least one other
number (a factor) other than itself
Definitions
• Prime Number – An integer whose
only factors are 1 and itself.
• Factor – a number that can divide
another number without a remainder.
• Prime Factors – an expression of
numbers that divides another integer
without a remainder where all the
factors are prime.
What numbers are prime?
• Let’s look at a number grid from 1 to
100 and see how they were
discovered.
Here’s How You Do It
2 3 4 5 6 7 8 9 10
Take out the number 1 1
because it is a special
11 12 13 14 15 16 17 18 19 20
number
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
Here’s How You Do It
2 3 4 5 6 7 8 9 10
Take out the number 1
because it is a special
11 12 13 14 15 16 17 18 19 20
number
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
Here’s How You Do It
2 3 4 5 6 7 8 9 10
Take out numbers that
have a composite
11 12 13 14 15 16 17 18 19 20
factor of 2
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
Here’s How You Do It
2
Take out numbers that
have a composite
11
factor of 2
3
5
7
9
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
Here’s How You Do It
2
3
5
7
9
11
13
15
17
19
Take out numbers that 21
have a composite
31
factor of 3
23
25
27
29
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
Here’s How You Do It
2
3
11
13
Take out numbers that
have a composite
31
factor of 3
23
41
37
55
73
49
59
67
77
85
95
19
29
47
65
83
91
25
43
61
7
17
35
53
71
5
79
89
97
Here’s How You Do It
2
11
3
13
23
31
41
Take out numbers that
have a composite
factor of 5
61
71
25
43
53
7
17
35
37
55
73
49
59
67
77
85
95
19
29
47
65
83
91
5
79
89
97
Here’s How You Do It
2
11
3
13
5
7
17
23
31
41
Take out numbers that
have a composite
factor of 5
61
71
29
37
43
47
53
49
59
67
73
77
83
91
19
79
89
97
Here’s How You Do It
2
11
3
13
5
7
17
23
31
41
29
37
43
47
53
Take out numbers that 61
have a composite
71
factor of 7
91
19
49
59
67
73
77
83
79
89
97
The PRIME Numbers!
2
11
3
13
5
7
17
23
31
41
29
37
43
47
53
Take out numbers that 61
have a composite
71
factor of 7
19
59
67
73
79
83
89
97
How Do We Know They Are
Prime?
• Composite numbers can be placed
into varying types of rectangles
• Prime numbers cannot
• Let’s look at that…
Composite Numbers
6
15
24
Prime Numbers
7
17
29
That’s It!
• A prime number cannot be divided by
anything other than 1 and itself.
This powerpoint was kindly donated to
www.worldofteaching.com
http://www.worldofteaching.com is home to over a
thousand powerpoints submitted by teachers. This is a
completely free site and requires no registration. Please
visit and I hope it will help in your teaching.