Transcript Chapter 5 Lesson 2 Rational Numbers Pgs. 205-209

Chapter 5 Lesson 2
Rational Numbers
Pgs. 205-209
What you will learn (maybe):
Write rational numbers as fractions
Identify and Classify rational numbers
Vocabulary:

Rational Number (205): A number that can be
written as a fraction. Terminating decimals are
rational numbers because they can be written as
a fraction with a denominator of 10, 100, 1000
and so on…..
Ex.) 0.75 = 3/4
28 = 28/1
1 1/4 = 5/4
_
-0.3 = - 1/3
Write Mixed Numbers and Integers as Fractions
Write 5 2/3 as a fraction.
2
17
Turn the Mixed #
into an improper
5 3 = 3
fraction
Write -3 as a fraction
-3 = -3
1
or
3
1
Write Terminating Decimals as Fractions
Write each decimal as a fraction or mixed number
in simplest form.
0.48 = 48
100
Simplify: 12
25
See the digit chart on pg. 206
6.375 =
Simplify:
6
375
1000
63
8
Write Repeating Decimals as Fractions
_
Write 0.8 as a fraction in simplest form
Let N represent the number: N= 0.888…..
Multiply each side by 10 since one digit repeats:10N = 10(.888…)
10N = 8.888…..
Subtract N from 10N to eleminate the repeating part. 0.888….
10N = 8.888…
- (N = 0.888…)
9N = 8
N= 8
9N = 8
9 9
9
Big Idea! Noteworthy!!
All rational numbers can be written as terminating or
repeating decimals.
Decimals that do not terminate or repeat are called
irrational numbers because they CANNOT be written
as fractions
Examples of irrational numbers:
Pi = 3.141592654….. ----> digits DO NOT repeat
4.232232223…….---->same blocks of digits DON’T
repeat
Refer to the Concept
Summary on Pg. 207
Identify all sets to which each number
belongs:
-6
Integer, Rational
2 4/5
Rational
0.914114111…
Irrational
You Try!
Write each number as a fraction.
-2 1/3
10
7 2/3
- 7/3
10
1
23
3
Write each number as a fraction or mixed number
in simplest form.
_
.8
6.35
4/5
6 7/20
-0.7
_ 7
9