LESSON: Rounding Decimals
READ: Rounding Decimals A Given Place Value
Rounding Decimals A Given Place Value
We can also use place value to help us in rounding numbers. Once again, we are going to follow the same rules that we did when rounding whole numbers except this time we will be rounding to the nearest whole or tenths, hundredths, thousandths, etc.
Example
Round .345 to the nearest tenth
To help us with this, let’s put the number in our place value chart.
Tens  Ones  
Tenths  Hundredths  Thousandths 
Ten Thousandths 


.  3  4  5  
Now we are rounding to the nearest tenth.
3 is in the tenths place.
4 is the digit to the right of the place we are rounding.
It is less than 5, so we leave the 3 alone.
Our answer is .3.
Notice that we don’t include the other digits because we are rounding to tenths. We could have put zeros in there, but it isn’t necessary.
Example
Round .567 to the nearest hundredth
To help us with this, let’s use our place value chart again.
Tens  Ones  
Tenths  Hundredths  Thousandths 
Ten Thousandths 


.  5  6  7  
Now we are rounding to the nearest hundredth.
The 6 is in the hundredths place.
The 7 is the digit to the right of the hundredths place.
Since a 7 is a 5 or greater, we round up to the next digit.
6 becomes 7.
Our answer is .57.
Notice in this case that the five is included. Because it is to the left of the place we are rounding, it remains part of the number.