Rounding Decimals
Learning Outcomes
- Round a decimal to a given place value
![In part a, a number line is shown with 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 and 3. There is a dot between 2.7 and 2.8 labeled as 2.72. In part b, a number line is shown with 2.70, 2.71, 2.72, 2.73, 2.74, 2.75, 2.76, 2.77, 2.78, 2.79, and 2.80. There is a dot at 2.72.](https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/277/2017/04/24221512/CNX_BMath_Figure_05_01_012.png)
Round a decimal.
- Locate the given place value and mark it with an arrow.
- Underline the digit to the right of the given place value.
- Is this digit greater than or equal to
- Yes - add to the digit in the given place value.
- No - do not change the digit in the given place value
- Rewrite the number, removing all digits to the right of the given place value.
example
Round to the nearest hundredth. SolutionLocate the hundredths place and mark it with an arrow. | ![]() |
Underline the digit to the right of the . | ![]() |
Because is greater than or equal to , add to the . | ![]() |
Rewrite the number, deleting all digits to the right of the hundredths place. | |
is rounded to the nearest hundredth. |
try it
[ohm_question]146242[/ohm_question]example
Round to the nearest- tenth
- whole number
Answer:
1. Round to the nearest tenth. | |
Locate the tenths place and mark it with an arrow. | ![]() |
Underline the digit to the right of the tenths digit. | ![]() |
Because is greater than or equal to , add to the . | ![]() |
Rewrite the number, deleting all digits to the right of the tenths place. | |
So, rounded to the nearest tenth is . |
2. Round to the nearest whole number. | |
Locate the ones place and mark it with an arrow. | ![]() |
Underline the digit to the right of the ones place. | ![]() |
Since is not greater than or equal to , do not add to the . | ![]() |
Rewrite the number, deleting all digits to the right of the ones place. | |
So rounded to the nearest whole number is . |