Rounding Whole Numbers
Learning Outcomes
- Identify the place value of a digit used for rounding
- Round a whole number to a specific place value
Round a whole number to a specific place value
- Locate the given place value. All digits to the left of that place value do not change.
- Underline the digit to the right of the given place value.
- Determine if this digit is greater than or equal to [latex]5[/latex].
- Yes—add [latex]1[/latex] to the digit in the given place value.
- No—do not change the digit in the given place value.
- Replace all digits to the right of the given place value with zeros.
example
Round [latex]843[/latex] to the nearest ten. SolutionLocate the tens place. | |
Underline the digit to the right of the tens place. | |
Since [latex]3[/latex] is less than [latex]5[/latex], do not change the digit in the tens place. | |
Replace all digits to the right of the tens place with zeros. | |
Rounding [latex]843[/latex] to the nearest ten gives [latex]840[/latex]. |
try it
Round to the nearest ten: [latex]157[/latex].Answer: [latex]160[/latex]
Round to the nearest ten: [latex]884[/latex].Answer: [latex]880[/latex]
Example
Round each number to the nearest hundred:- [latex]23,658[/latex]
- [latex]3,978[/latex]
Answer:
1. | |
Locate the hundreds place. | |
The digit of the right of the hundreds place is [latex]5[/latex]. Underline the digit to the right of the hundreds place. | |
Since [latex]5[/latex] is greater than or equal to [latex]5[/latex], round up by adding [latex]1[/latex] to the digit in the hundreds place. Then replace all digits to the right of the hundreds place with zeros. | So 23,658 rounded to the nearest hundred is 23,700. |
2. | |
Locate the hundreds place. | |
Underline the digit to the right of the hundreds place. | |
The digit to the right of the hundreds place is [latex]7[/latex]. Since [latex]7[/latex] is greater than or equal to [latex]5[/latex], round up by added [latex]1[/latex] to the [latex]9[/latex]. Then place all digits to the right of the hundreds place with zeros. | So 3,978 rounded to the nearest hundred is 4,000. |
try it
Round to the nearest hundred: [latex]17,852[/latex].Answer: [latex-display]17,900[/latex-display]
Round to the nearest hundred: [latex]4,951[/latex].Answer: [latex-display]5,000[/latex-display]
example
Round each number to the nearest thousand:- [latex]147,032[/latex]
- [latex]29,504[/latex]
Answer:
1. | |
Locate the thousands place. Underline the digit to the right of the thousands place. | |
The digit to the right of the thousands place is [latex]0[/latex]. Since [latex]0[/latex] is less than [latex]5[/latex], we do not change the digit in the thousands place. | |
We then replace all digits to the right of the thousands pace with zeros. | So 147,032 rounded to the nearest thousand is 147,000. |
2. | |
Locate the thousands place. | |
ⓑUnderline the digit to the right of the thousands place. | |
The digit to the right of the thousands place is [latex]5[/latex]. Since [latex]5[/latex] is greater than or equal to [latex]5[/latex], round up by adding [latex]1[/latex] to the [latex]9[/latex]. Then replace all digits to the right of the thousands place with zeros. | So 29,504 rounded to the nearest thousand is 30,000. |
Licenses & Attributions
CC licensed content, Shared previously
- Ex: Rounding to the Various Place Values - Number Line / Formal Rules . Authored by: James Sousa (Mathispower4u.com). License: CC BY: Attribution.
- Question ID: 143029, 143030. Authored by: Alyson Day. License: CC BY: Attribution. License terms: IMathAS Community License CC-BY + GPL.
CC licensed content, Specific attribution
- Prealgebra. Provided by: OpenStax License: CC BY: Attribution. License terms: Download for free at http://cnx.org/contents/[email protected].