1. Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Chapter 4 Decimals

2. Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. 4.2 Order and Rounding

3. Martin-Gay, Basic Mathematics, 4e 33 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Comparing Decimals One way to compare decimals is to compare their graphs on a number line. Numbers to the left are smaller and numbers to the right are larger. Comparing Two Decimals

4. Martin-Gay, Basic Mathematics, 4e 44 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Comparing Two Decimals

5. Martin-Gay, Basic Mathematics, 4e 55 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Insert, or = to form a true statement. 0.645 0.632 The tenths places are the same. The hundredths places are different. Since 4 > 3, 0.645 > 0.632

6. Martin-Gay, Basic Mathematics, 4e 66 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Write the decimals in order from smallest to largest. 2.007, 3.517, 2.3, 2.03 By comparing the ones digit, the decimal 3.517 is the largest number. To write the rest of the decimals in order, we compare digits to the right of the decimal point. We can insert zeros to help compare. 2.007 2.03 2.3 3.517 Example

7. Martin-Gay, Basic Mathematics, 4e 77 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Problems – insert, or =Answers 1. 2. 3. 4. P 257 Practice Problems Comparing Decimals

8. Martin-Gay, Basic Mathematics, 4e 88 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Rounding Decimals

9. Martin-Gay, Basic Mathematics, 4e 99 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Round 0.5942 to the nearest thousandth. Step 1: Locate the digit to the right of the given place value. 0.5942 2 is to the right of the thousandth place value. Step 2: Since the digit to the right is less than 5, we delete it and all digits to its right. Thus 0.5942 rounded to the nearest thousandth is 0.594

10. Martin-Gay, Basic Mathematics, 4e 10 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Round $0.067 to the nearest cent. Step 1: Locate the digit to the right of the given place value. $0.067 7 is to the right of the hundredths place value Step 2: Since the digit to the right is more than 5, we round up. Thus $0.067 rounds to $0.07.

11. Martin-Gay, Basic Mathematics, 4e 11 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example An aquarium costs $245.69. Round the price to the nearest dollar. The nearest dollar means the ones place. Locate the digit to the right of the ones place. $245.69 6 is to the right of the ones place value Thus $245.69 rounds to $246.00.

12. Martin-Gay, Basic Mathematics, 4e 12 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Problems – insert, or =Answers 5. 6. 7. 8. P 258 Practice Problems Rounding Decimals Round 123.7814 to the nearest thousandth. Round 123.7814 to the nearest tenth In Citation, the price of a gallon of gasoline is $2.1589. Round this to the nearest cent. Round $1.095 to the nearest cent.

13. Martin-Gay, Basic Mathematics, 4e 13 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Problems – insert, or =Answers 9. P 259 Practice Problems Rounding Decimals Water bills in Gotham City are always rounded to the nearest dollar. Lois’s water bill was $24.62. Round her bill to the nearest dollar.

14. Martin-Gay, Basic Mathematics, 4e 14 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. DONE