Basic Math & Pre-Algebra All-in-One For Dummies (+ Chapter Quizzes Online)
Explore Book Buy On AmazonRounding decimals works almost exactly the same as rounding numbers. You will usually need to round a decimal either to a whole number or to one or two decimal places.
To round a decimal to a whole number, focus on the ones digit and the tenths digit. Round the decimal either up or down to the nearest whole number, dropping the decimal point:
![image0.png](https://www.dummies.com/wp-content/uploads/215975.image0.png)
When the tenths digit is 5 (or greater), round the decimal up:
![image1.png](https://www.dummies.com/wp-content/uploads/215976.image1.png)
If the decimal has other decimal digits, just drop them:
![image2.png](https://www.dummies.com/wp-content/uploads/215977.image2.png)
Occasionally, a small change to the ones digits affects the other digits. (This may remind you of when the odometer in your car rolls a bunch of 9s over to 0s):
![image3.png](https://www.dummies.com/wp-content/uploads/215978.image3.png)
The same basic idea applies to rounding a decimal to any number of places. For example, to round a decimal to one decimal place, focus on the first and second decimal places (that is, the tenths and hundredths places):
![image4.png](https://www.dummies.com/wp-content/uploads/215979.image4.png)
To round a decimal to two decimal places, focus on the second and third decimal places (that is, the hundredths and thousandths places):
![image5.png](https://www.dummies.com/wp-content/uploads/215980.image5.png)