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1,001 Basic Math and Pre-Algebra Practice Problems For Dummies by Mark Zegarelli

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Chapter 23

Answers

1.    140

The ones digit is 6, so round up by adding 1 to the tens digit (3 + 1 = 4) and changing the 6 to 0: 136 140.

2.    220

The ones digit is 4, so round down by changing the 4 to 0: 224 220.

3.    2,500

The tens digit is 9, so round up by adding 1 to the hundreds digit (4 + 1 = 5) and changing both the 9 and the 2 to 0s: 2,492 2,500.

4.    909,100

The tens digit is 9, so round up by adding 1 to the hundreds digit (0 + 1 = 1) and changing the 9 to 0: 909,090 909,100.

5.    9,000

The hundreds digit is 0, so round down by changing every digit to the right of the thousands digit to 0: 9,099 9,000.

6.    235,000,000

The hundred-thousands digit is 5, so round up by adding 1 to the millions digit (4 + 1 = 5) and changing every digit to the right of the millions digit to 0: 234,567,890 235,000,000.

7.    68

Stack the numbers and add the columns from right to left.

9781118446454-eq230001.eps

8.    266

Stack the numbers and add the columns from right to left.

9781118446454-eq230002.eps

9.    2,310

Stack the numbers and add the columns from right to left.

9781118446454-eq230003.eps

10.    9,343

Stack the numbers and add the columns from right to left.

11.    406,055

Stack the numbers and add the columns from right to left. ...

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