Mathematics Essentials Q1

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.