Download Textbook Section 4.2

Musical Chairs
• No more than 2 people at one table who
have been at the same table before.
• I suggest that one person remain at the
table you have been at for the past few
weeks and the rest move, making sure
that there is no more than one person at
your new table with whom you have
previously shared a table.
Finding factors of a number
• Use the beans to find factors of 24
Count out 24 beans
We know that products can be illustrated
using a rectangular model
Make a rectangle using the beans
What are the numbers you multiply to get 24?
Can you arrange the beans into a different
rectangle?
What product does this represent?
How many different rectangles can you
make?
Count out 11 beans.
How many rectangles can you make with
11 beans?
The Sieve of Eratosthenes
• Prime Number
Divisible only by 1 and itself
• Finding prime numbers using the sieve
Sieve of Eratosthenes
1
11
21
31
41
51
61
71
81
91
2
12
22
32
42
52
62
72
82
92
3
13
23
33
43
53
63
73
83
93
4
14
24
34
44
54
64
74
84
94
5
15
25
35
45
55
65
75
85
95
6
16
26
36
46
56
66
76
86
96
7
17
27
37
47
57
67
77
87
97
8
18
28
38
48
58
68
78
88
98
9
10
19
20
29
30
39
40
49
50
59
60
69
70
79
80
89
90
99 100
Names for these numbers
11 is an example of a
24 is an example of a
Factors of 24
• List
How should they be ordered?
• How do you know you have them all?
Exploration 4.3
• Do #1 yourself, compare answer with the
others in your group.
• Do #2 with the following numbers
60
72
Methods of factoring
Factorization
• Factorization is writing a number as a
product of factors.
24
60
Prime Factorization
• A factorization of the number in which all
of the factors are prime numbers.
10
12
Prime Factorization
• 24
• 25
Prime Factorization
60 Using a factor tree to do prime
factorization
• 112
• Exploration 4.3 is due on Monday
#1,2,6,7,8 along with some exercises
from the textbook.
Please put the exploration on a separate
paper than the textbook problems. All of
the textbook problems may be on the
same paper.