2. 5.2 Rounding Decimal Numbers
Chapter 5 Rational Numbers: Positive and
Negative Decimals

3. 5.2 Rounding Decimal Numbers
Objectives
Learn the rules for rounding decimals.
Round decimals to any given place.
Round money amounts to the nearest cent or nearest dollar.
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4. Objective 1: Learn the rules for rounding decimals.
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5. Objective 2: Round decimals to any given place.
Example
Round to the nearest thousandth.
Is it closer to or to ?
Step 1
Draw a “cut-off ” line after the thousandths place.
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6. Objective 2: Round decimals to any given place.
Example
(continued)
Step 2
Look only at the first digit you are cutting off. Ignore the other digits you are cutting off.
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7. Objective 2: Round decimals to any given place.
Example
(continued)
Step 3
If the first digit you are cutting off is 5 or more, round up the part of the number you are keeping.
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8. Objective 2: Identify the place value of a digit.
Decimal places are the number of digits to the right of the decimal point.
has three decimal places.
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9. Objective 2: Round decimals to any given place.
Example
Round to the nearest tenth.
Is it closer to 5.3 or to 5.4?
Step 1
Draw a “cut-off ” line after the tenths place.
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10. Objective 2: Round decimals to any given place.
Example
(continued)
Step 2
Step 3
rounded to the nearest tenth is You may write ≈ 5.3.
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11. Objective 2: Round decimals to any given place.
Example
Round to the nearest hundredth.
Is it closer to 0.69 or 0.70?
Step 1
Draw a “cut-off ” line after the hundredths place.
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Sec

12. Objective 2: Round decimals to any given place.
Example
(continued)
Step 2
Step 3
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13. Objective 2: Round decimals to any given place.
Example
(continued)
rounded to the nearest hundredth is You must write the 0 in the hundredths place. You may write ≈ 0.70.
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Sec

14. Objective 2: Round decimals to any given place.
Example
Round to the nearest thousandth.
Is it closer to or 0.019?
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15. Objective 3: Round money amounts to the nearest cent or nearest dollar.
Example
Round $ to the nearest cent.
Is it closer to $2.42 or $2.43?
$ rounds to $2.42.
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16. Objective 3: Round money amounts to the nearest cent or nearest dollar.
Example
Round $0.695 to the nearest cent.
Is it closer to $0.69 or $0.70?
$0.695 rounds to $0.70.
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17. Objective 3: Round money amounts to the nearest cent or nearest dollar.
Example
Round $48.69 to the nearest dollar.
Is it closer to $48 or $49?
$48.69 rounds to $49.
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18. Objective 3: Round money amounts to the nearest cent or nearest dollar.
Example
Round $ to the nearest dollar.
Is it closer to $594 or $595?
$ rounds to $594.
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19. Objective 3: Round money amounts to the nearest cent or nearest dollar.
Example
Round $ to the nearest dollar.
Is it closer to $399 or $400?
$ rounds to $400.
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Sec

20. Objective 3: Round money amounts to the nearest cent or nearest dollar.
Example
Round $0.61 to the nearest dollar.
Is it closer to $0 or $1?
$0.61 rounds to $1.
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Sec