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

2. Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. 4.5 Dividing Decimals and Order of Operations

3. Martin-Gay, Developmental Mathematics, 2e 33 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Dividing Decimals Dividing decimal numbers is similar to dividing whole numbers. The only difference is that we place a decimal point in the quotient. Dividing by a Whole Number Step 1: Place the decimal point in the quotient directly above the decimal point in the dividend. Step 2: Divide as with whole numbers.

4. Martin-Gay, Developmental Mathematics, 2e 44 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Dividing Decimals Dividing by a Whole NumberExample Step 1 : Place the decimal point in the quotient directly above the decimal point in the dividend. Step 2: Divide as with whole numbers. 5.9

5. Martin-Gay, Developmental Mathematics, 2e 55 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Divide: 219.2÷8. divisor dividend quotient Check:

6. Martin-Gay, Developmental Mathematics, 2e 66 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Divide: 0.6÷4. divisor dividend quotient Check:

7. Martin-Gay, Developmental Mathematics, 2e 77 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Dividing by a Decimals If the divisor is not a whole number, before we divide we need to move the decimal point to the right until the divisor is a whole number.

8. Martin-Gay, Developmental Mathematics, 2e 88 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Divide: 6.888÷2.8. becomes 2.46

9. Martin-Gay, Developmental Mathematics, 2e 99 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Estimating When Dividing Decimals Example: Divide: 0.54÷12. Then estimate to whether the proposed result is reasonable. Exact Estimate The estimate is 0.05, so 0.045 is reasonable.

10. Martin-Gay, Developmental Mathematics, 2e 10 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Dividing by Powers Dividing Decimals by Powers of 10 such as 10, 100 or 1000 Move the decimal point of the dividend to the left the same number of places there are zeros in the power of 10.

11. Martin-Gay, Developmental Mathematics, 2e 11 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Divide. a. b. = 0.5486 Move the decimal point 3 places to the left. = 0.068 Move the decimal point 1 place to the left.

12. Martin-Gay, Developmental Mathematics, 2e 12 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Order of Operations 1. Perform all operations within parentheses ( ), brackets [ ], or other grouping symbols such as fraction bars or square roots, starting with the innermost set. 2. Evaluate any expressions with exponents. 3. Multiply or divide in order from left to right. 4. Add or subtract in order from left to right.

13. Martin-Gay, Developmental Mathematics, 2e 13 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Simplify 1.4(2 – 1.8).