Rounding decimals?
When you do not need to speak or write about exact quantities or measures, learning to round decimals can be useful. Rounding decimals is useful when making an estimation.
The process is similar to when you are rounding whole numbers.
Numbers that end in a number smaller than 5 are rounded down to the nearest tenth or hundredth.
Numbers that end in a 5 or a number greater than 5 are rounded up to the nearest tenth or hundredth.
This number line shows how this works for decimals between 1.6 and 1.7.

Quiz: Rounding to one decimal place
Test out your knowledge of how to round decimals with this quiz, then read on to complete the page.
Rounding decimals using place value charts
A place value chart can be really helpful when rounding decimals.
They help you see the value of each digit within a number.
Take the number 7.54.
It has 7 ones, 5 tenths and 4 hundredths.

Let’s round the number 7.54 to the nearest tenth.
Here, 4 hundredths is less than 5 hundredths, so it is rounded down.
When it is rounded down, 7.54 becomes 7.5.
Now, let's try rounding the number 7.56 to the nearest tenth.

6 hundredths is more than 5 hundredths, so it is rounded up to the nearest tenth.
When it is rounded up, 7.56 becomes 7.6.
Rounding decimals using a number line
Here is a number line from 6.3 to 6.4. It goes up in intervals of one hundredths.
Explore the slideshow to find out which numbers should be rounded up and down when rounding to the nearest tenth.
Image caption, , if the hundredths digit is 5 or above, it is rounded up to the nearest tenth.
Image caption, 6.35, 6.36, 6.37, 6.38 and 6.39 are all rounded up to 6.4.
Image caption, If the hundredth digit is smaller than 5, it is rounded down to the nearest tenth.
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Rounding decimals using place value counters
Take a look at these place value counters representing 2.64.
You can use the counters to work out whether you should round up or down to the nearest tenth.
, one hundredth is 0.01 and ten hundredths make one tenth which is 0.1.
Explore the slideshow to find out whether the number should be rounded to 2.6 or 2.7.
Image caption, Here is the number 2.64 represented with place value counters. It has 2 ones, 6 tenths and 4 hundredths.
Image caption, To round 2.64 up to 2.7, you need to add 6 more hundredths counters.
Image caption, To round 2.64 down to 2.6, you need to subtract 4 hundredths counters.
Image caption, So, 2.64 is closer to 2.6 and so it is rounded down.
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Example 1

Round this number to one decimal place.
✓ 9.45 rounded to one decimal place is 9.5.

, if the number in the hundredths column is 5 or above, it is rounded up to the nearest tenth.
The nearest tenth is 5, so the correct answer is 9.5
Example 2

Round 9.84 to one decimal place.
You can use the number line to help you round.
✓ 9.84 rounded to one decimal place is 9.8.

, the number in the hundredth column is less than 5, so it is rounded down to the nearest tenth.
The nearest tenth is 8, so the correct answer is 9.8.
Example 3

These place value counters represent a number. Round the number to the nearest tenth.
✓ Rounded to the nearest tenth, the number is 4.6.
The counters represent the number 4.56.
You would need to add 4 hundredth counters to make 4.6.

4.56 + 0.04 = 4.6
Or you would need to subtract 6 hundredth counters to make 4.5.

4.56 - 0.06 = 4.5
So, 4.56 is closer to 4.6.
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