1. 3-9 Equivalent Fractions and Decimals Warm Up Problem of the Day
Course 2
Warm Up
Problem of the Day
Lesson Presentation

2. 3-9 Equivalent Fractions and Decimals Warm Up
Course 2
3-9
Equivalent Fractions and Decimals
Warm Up
Write each fraction in the simplest form. 1. 2. 3. 4. 4 12 1 3 18 46 9 23 21 63 1 3
100 72 25 18
or 1 7

3. 3-9 Equivalent Fractions and Decimals Problem of the Day
Course 2
3-9
Equivalent Fractions and Decimals
Problem of the Day
For Martin’s 4-H project he recorded how much a bean plant grew each week. The first week the plant grew of an inch. It grew of an inch the second week and of an inch the third week. During which week did the plant grow the least? 4 7 7 8 7 9
week 1

4. Course 2
3-9
Equivalent Fractions and Decimals
Learn to write fractions as decimals, and vice versa, and to determine whether a decimal is terminating or repeating.

5. Insert Lesson Title Here
Course 2
3-9
Equivalent Fractions and Decimals
Insert Lesson Title Here
Vocabulary
terminating decimal
repeating decimal

6. 3-9 Equivalent Fractions and Decimals
Course 2
3-9
Equivalent Fractions and Decimals
In baseball, a player’s batting average compares the number of hits with the number of times the player has been at bat The statistics on the next slide are for the 2001 Major League Baseball season.

7. Batting Average (thousandths)
Course 2
3-9
Equivalent Fractions and Decimals
Player
Hits
At Bats
Batting Average (thousandths)
Mark Grace
Cal Ripken, Jr.
Ivan Rodriguez
Sammy Sosa
Hits
at Bats
142
476
142
476
142 ÷ 476 ≈ 0.298
114
477
114
477
114 ÷ 477 ≈ 0.239
136
442
136
442
136 ÷ 442 ≈ 0.308
289
577
189
577
289 ÷ 577 ≈ 0.328
To convert a fraction to a decimal, divide the numerator by the denominator.

8. Additional Example 1: Writing Fractions as Decimals
Course 2
3-9
Equivalent Fractions and Decimals
Additional Example 1: Writing Fractions as Decimals
Write each fraction as a decimal. Round to the nearest hundredth, if necessary. 1 4 9 5 5 3 A. B. C. 1 .8 1 .6 6 6
0.2 5
1.00 4 5
9.0 3
5.000
– 8
– 3
– 5 20 40 20
– 20
– 40
– 18 20
– 18 1 4 9 5
= 1.8 5 3
= 0.25 20
≈ 1.67
– 18 2

9. 3-9 Equivalent Fractions and Decimals Helpful Hint
Course 2
3-9
Equivalent Fractions and Decimals
You can use a calculator to check your division: 1 9 5 33
Helpful Hint ÷ 4 =
0.25
1.8 3
1.66…

10. Insert Lesson Title Here
Course 2
3-9
Equivalent Fractions and Decimals
Insert Lesson Title Here
Try This: Example 1
Write each fraction as a decimal. Round to the nearest hundredth, if necessary. 3 4 6 5 7 3 A. B. C. 1 .2 2 .3 3 3
0.7 5
3.00 4 5
6.0 3
7.000
– 2 8
– 6
– 5 20 10 10
– 20
– 10
– 9 10
– 9 3 4 6 5
= 1.2 7 3
= 0.75 10
≈ 2.33
– 9 1

11. 3-9 Equivalent Fractions and Decimals
Course 2
3-9
Equivalent Fractions and Decimals
The decimals 0.75 and 1.2 in Example 1 are terminating decimals because the decimal comes to an end. The decimal 0.333…is a repeating decimal because the decimal repeats a pattern forever. You can also write a repeating decimal with a bar over the repeating part.
0.333… = … = … = 0.72

12. 3-9 Equivalent Fractions and Decimals
Course 2
3-9
Equivalent Fractions and Decimals
You can use place value to convert a terminating decimal to a fraction.
Place
Thousands
Hundreds
Tens
Ones
Tenths
Hundredths
Thousandths
Place
Value
1,000
100 10 1
0.1 =
0.01 =
0.001 =

13. Additional Example 2: Writing Decimals as Fractions
Course 2
3-9
Equivalent Fractions and Decimals
Additional Example 2: Writing Decimals as Fractions
Write each decimal as a fraction in simplest form. A
B. –0.6
C. 1.55 18
1,000 6 10
0.018 =
155
100
–0.6 = –
1.55 =
18 ÷ 2
1,000 ÷ 2
6 ÷ 2
10 ÷ 2
155 ÷ 5
100 ÷ 5 =
= – = 11 20 3 5 31 20 9
500
= –
or 1 = =

14. Insert Lesson Title Here
Course 2
3-9
Equivalent Fractions and Decimals
Insert Lesson Title Here
Try This: Example 2
Write each decimal as a fraction in simplest form. A
B. –0.8
C. 1.30 15
1,000 8 10
0.015 =
130
100
–0.8 = –
1.30 =
15 ÷ 5
1,000 ÷ 5
8 ÷ 2
10 ÷ 2
130 ÷ 10
100 ÷ 10 =
= – = 3 10 4 5 13 10 3
200
= –
or 1 = =

15. Additional Example 3: Sports Application
Course 2
3-9
Equivalent Fractions and Decimals
Additional Example 3: Sports Application
A football player completed 1,546 of the 3,875 passes he attempted. Find his completion rate. Write your answer as a decimal rounded to the nearest thousandth.
Fraction
What the Calculator Shows
Completion Rate
1,546
3,875
1546 ÷
ENTER
3875
0.399
His completion rate is

16. Insert Lesson Title Here
Course 2
3-9
Equivalent Fractions and Decimals
Insert Lesson Title Here
Try This: Example 3
Johnny Unitas, a former professional quarterback, completed 2,830 of the 5,186 passes he attempted. Find his completion rate. Write your answer as a decimal rounded to the nearest thousandth.
Fraction
What the Calculator Shows
Completion Rate
2,830
5,186
2830 ÷
ENTER
5186
0.546
His completion rate is

17. Insert Lesson Title Here
Course 2
3-9
Equivalent Fractions and Decimals
Insert Lesson Title Here
Lesson Quiz
Write each fraction as a decimal. 1.
Write each decimal as a fraction in simplest form.
5. If your soccer team wins 21 out of 30 games, what is your team’s winning rate? 16 5 21 8
3.2 2.
2.625 21 50 69 8
0.70