lesson 1 menu five-minute check (over chapter 1) main idea and vocabulary targeted teks key concept:...

Five-Minute Check (over Chapter 1)

Main Idea and Vocabulary

Targeted TEKS

Key Concept: Rational Numbers

Example 1: Write a Fraction as a Decimal

Example 2: Write a Mixed Number as a Decimal

Example 3: Round a Repeating Decimal

Example 4: Write a Decimal as a Fraction

Example 5: Write a Decimal as a Fraction

• rational number

• terminating decimal• repeating decimal• bar notation

• Express rational numbers as decimals and decimals as fractions.

Reinforcement of TEKS 7.1 The student represents and uses numbers in a variety of equivalent forms. (B) Convert between fractions, decimals, whole numbers, and percents mentally, on paper, or with a calculator.

Write a Fraction as a Decimal

Write as a decimal.

0

–160

.1

–128

8

0–112

75

14

12

80–80

0

Divide 3 by 16.

Write a Fraction as a Decimal

Answer: 0.1875

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

A. 0.0515

B. 0.0625

C. 0.0875

D. 0.16

Write a Repeating Decimal

You can divide as shown in Example 1 or use a calculator.

Answer:

–35 11 –3.18181818ENTER÷

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 5.1111...

B. 5.1515...

C. 5.2222...

D. 5.9999...

AGRICULTURE A Texas farmer lost the fruit on 8 of 15 orange trees because of unexpected freezing temperatures. Find the fraction of the orange trees that did not produce fruit. Express your answer as a decimal rounded to the nearest thousandth.

To find the fraction of trees that did not produce fruit, divide the number of lost trees, 8, by the total number of trees, 15.

Round a Repeating Decimal

8 15 0.5333333333ENTER÷

Look at the digit to the right of the thousandths place. Round down since 3 < 5.

Answer: The fraction of fruit trees that did not produce fruit was 0.533.

Round a Repeating Decimal

1. A

2. B

3. C

4. D

0%0%0%0%

A B C D

A. 0.094

B. 0.148

C. 0.182

D. 0.252

SCHOOL In Mrs. Townley’s eighth grade science class, 4 out of 22 students did not turn in their homework. Find the fraction of the students who did not turn in their homework. Express your answer as a decimal rounded to the nearest thousandth.

Write 0.32 as a fraction.

0.32 is 32 hundredths.

Write a Decimal as a Fraction

Simplify.

Answer:

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

Write 0.16 as a fraction.

A.

B.

C.

D.

Write a Decimal as a Fraction

ALGEBRA Write 2.7 as a mixed number.

Multiply N by 10 because 1 digit repeats.

Let N = 2.7 or 2.777... . Then 10N = 27.777... .

Subtract N = 2.777... to eliminate the repeating part, 0.777... .

Divide each side by 9.

Write a Decimal as a Fraction

Answer:

9N = 25 10N – 1N = 9N

10N = 27.777...–1N = 2.777...

Simplify.

A. A

B. B

C. C

D. D A B C D

0% 0%0%0%

ALGEBRA Write 1.7 as a mixed number.

A.

B.

C.

D.