2-10

1. 2-10 Equivalent Fractions and Decimals Course 2 Warm Up Problem of the Day Lesson Presentation

2. 2-10 Equivalent Fractions and Decimals Course 2 Learn to write fractions as decimals, and vice versa, and to determine whether a decimal is terminating or repeating.

3. 2-10 Equivalent Fractions and Decimals Course 2 Insert Lesson Title Here Vocabulary terminating decimal repeating decimal

4. 2-10 Equivalent Fractions and Decimals Course 2 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 2004 Major League Baseball season.

5. 2-10 Equivalent Fractions and Decimals Course 2 Hits at Bats 172 544 544 172 ÷ 544 ≈ 0.316 172 172 601 172 601 172 ÷ 601 ≈ 0.286 To convert a fraction to a decimal, divide the numerator by the denominator.

6. 2-10 Equivalent Fractions and Decimals 1.00 Course 2 Additional Example 1: Writing Fractions as Decimals Write each fraction as a decimal. Round to the nearest hundredth, if necessary. 9 5 5 3 1 4 B. C. A. 1 .8 1 .6 6 6 0.2 5 9.0 5 5.000 3 4 – 8 – 3 – 5 20 20 40 – 20 – 18 – 40 20 0 0 – 18 9 5 5 3 1 4 = 1.8 ≈ 1.67 = 0.25 20 – 18 2

7. 2-10 Equivalent Fractions and Decimals Helpful Hint You can use a calculator to check your division: 1 9 5 33 4 = 0.25 ÷ 1.8 5 ÷ = 3 1.66… ÷ = Course 2

8. 2-10 Equivalent Fractions and Decimals 3.00 Course 2 Insert Lesson Title Here Check It Out: Example 1 Write each fraction as a decimal. Round to the nearest hundredth, if necessary. 6 5 7 3 3 4 B. C. A. 1 .2 2 .3 3 3 0.7 5 6.0 5 7.000 3 4 – 2 8 – 6 – 5 20 10 10 – 20 – 9 – 10 10 0 0 – 9 6 5 7 3 3 4 = 1.2 ≈ 2.33 = 0.75 10 – 9 1

9. 2-10 Equivalent Fractions and Decimals Course 2 The decimals 0.75 and 1.2 in Example 1 are terminating decimals because the decimals 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… = 0.3 0.8333… = 0.83 0.727272… = 0.72

10. 2-10 Equivalent Fractions and Decimals Course 2 Additional Example 2: Using Mental Math to Write Fractions as Decimals Write each fraction as a decimal. 4 5 A. Multiply to get a power of ten in the denominator. 4 5 2 2 8 10 = x = 0.8 37 50 B. Multiply to get a power of ten in the denominator. 37 50 2 2 74 100 = x = 0.74

11. 2-10 Equivalent Fractions and Decimals Course 2 Check It Out: Example 2 Write each fraction as a decimal. 3 5 A. Multiply to get a power of ten in the denominator. 3 5 2 2 6 10 = x = 0.6 18 25 B. Multiply to get a power of ten in the denominator. 18 25 4 4 72 100 = x = 0.72

12. 2-10 Equivalent Fractions and Decimals Reading Math You read the decimal 0.018 as “eighteen thousandths.” Course 2 Additional Example 3: Writing Decimals as Fractions Write each decimal as a fraction in simplest form. B. 1.55 A. 0.018 18 1,000 155 100 0.018 = 1.55 = 18 ÷ 2 1,000 ÷ 2 155 ÷ 5 100 ÷ 5 = = 31 20 11 20 9 500 or 1 = =

13. 2-10 Equivalent Fractions and Decimals Course 2 Insert Lesson Title Here Check It Out: Example 3 Write each decimal as a fraction in simplest form. B. 1.30 A. 0.015 15 1,000 130 100 0.015 = 1.30 = 130 ÷ 10 100 ÷ 10 15 ÷ 5 1,000 ÷ 5 = = 3 200 3 10 13 10 = or 1 =

14. 2-10 Equivalent Fractions and Decimals Course 2 Additional Example 4: 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. Completion Rate What the Calculator Shows Fraction 1,546 3,875 ENTER ÷ 0.398967742 0.399 1546 3875 His completion rate is 0.399.

15. 2-10 Equivalent Fractions and Decimals Course 2 Insert Lesson Title Here Check It Out: Example 4 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. What the Calculator Shows Fraction Completion Rate 2,830 5,186 ENTER ÷ 0.546 0.54569996 2830 5186 His completion rate is 0.546.