Main Idea and New Vocabulary Key Concept: Rational Numbers Example 1: Write a Fraction as a Decimal Example 2: Write a Fraction as a Decimal Example 3: Real-World Example Example 4: Write Decimals as Fractions Example 5: Write Decimals as Fractions Lesson Menu

Express rational numbers as decimals and decimals as fractions. terminating decimal repeating decimal Main Idea/Vocabulary

Key Concept

Write a Fraction as a Decimal Write as a decimal. means 3 ÷ 16. .1 8 7 5 Divide 3 by 16. Example 1

Write a Fraction as a Decimal Answer: 0.1875 Example 1

Write as a decimal. A. 0.55 B. 0.5625 C. 0.916 D. 1.7 _ Example 1 CYP

Write a Fraction as a Decimal Write as a decimal. can be written as . Divide 35 by 11 and add a negative sign. 3 –33 20 –11 90 –88 2 Example 2

Write a Fraction as a Decimal Answer: Example 2

Write as a decimal. A. B. C. 5.5 D. 5.7 Example 2 CYP

FRUIT When Juliana went strawberry picking, 28 of the 54 strawberries she picked weighed less than 2 ounces. To the nearest thousandth, find the fraction of the strawberries that weighed less than 2 ounces. To find the fraction of the strawberries that weighed less than 2 ounces, divide the number of strawberries that weighed less than 2 ounces, 28, by the total number of strawberries, 54. 28  54 ENTER 0.5185185185 Look at the digit to the right of the thousandths place. Since the digit is 5, round up. Example 3

Answer:. The fraction of the strawberries that Answer: The fraction of the strawberries that weighed less than 2 ounces was 0.519. Example 3

SCHOOL In Mrs. Townley’s eighth grade science class, 4 out of 22 students did not turn in their homework. To the nearest thousandth find the fraction of students who did not turn in their homework. A. 0.094 B. 0.148 C. 0.182 D. 0.252 Example 3 CYP

Write a Fraction as a Decimal Write 0.32 as a fraction. 0.32 0.32 is 32 hundredths. Simplify. Answer: Example 4

Write 0.65 as a fraction. A. B. C. D. Example 4 CYP

Write Decimals as Fractions ALGEBRA Write as a mixed number in simplest form. Assign a variable to the value . Let N = 2.777... . Then perform operations on N to determine its fractional value. Example 5

Write Decimals as Fractions 10(N) = 10(2.777...) Multiply each side by 10 because 1 digit repeats. 10N = 27.777... Multiplying by 10 moves the decimal point 1 place to the right. − N = 2.777... Subtract N = 0.777... to eliminate the repeating part. 9N = 25 Simplify. N = Divide each side by 9. __ 9 25 Answer: Example 5

Write –0.45 as a fraction in simplest form. __ A. B. C. D. Example 5 CYP