Rounding Off - Definition, Rules, Examples (2024)

Rounding Rules for Whole Numbers

Rounding rules for whole numbers are as follows:

• To get an accurate final result, always choose the smaller place value.
• Look for the next smaller place which is towards the right of the number that is being rounded off. For example, if you are rounding off a digit from the tens place, look for a digit in the one’s place.
• If the digit in the smallest place is less than 5, then the digit is left untouched. Any number of digits after that number becomes zero and this is known as rounding down.
• If the digit in the smallest place is greater than or equal to 5, then the digit is added with +1. Any digits after that number become zero and this is known asrounding up.

Rounding Rules for Decimal Numbers

Rounding rules for decimal numbers are as follows:

• Determine the rounding digit and look at its righthand side.
• If the digits on the right-hand side are less than 5, consider them as equal to zero.
• If the digits on the right-hand side are greater than or equal to 5, then add +1 to that digit and consider all other digits as zero.

Learn more about errors in arithmetic operation here.

Example of How to Round Off

Round to Nearest Hundred

Let’s consider the number 3350. To round off to the nearest significant number, consider hundreds places and follow the steps given below:

• Identify the digit present in the hundreds place: 3
• Identify the next smallest place in the number: 5
• If the smallest place digit is greater than or equal to 5, then round up the digit.
• Now add +1 to the digit in the hundreds place. 3+1=4. Therefore, the other digits become zero.
• So the final number is 3400.

Round to Nearest Ten

Let’s consider the number 313.5. To round off to the nearest significant number, consider tens place and follow the steps as given below:

• Identify the digit present in the tens place: 1
• Identify the next smallest place in the number: 3
• If the smallest place digit is greater than or equal to 5, then round up the digit.
• Since the digit in the smallest place is less than 5, a round down has to be done and also the digit remains unchanged.
• Every other digit becomes zero.
• So the final number is 310.

Round to Nearest Ten

Let’s consider the number 499. To round off to the nearest significant number, consider tens place and follow the steps as given below:

• Identify the digit present in the tens place: 9
• Identify the next smallest place in the number: 9
• If the smallest place digit is greater than or equal to 5, then round up the digit.
• As the digit in the one place is greater than 5, +1 has to be added.
• Therefore, 9+1=10 and the 1 is carried to the next place.
• So the final number is 500.

Round to Nearest Tenth

Let’s consider the number 0.73. To round off to the nearest significant number, consider tenths place and follow the steps as given below:

• Identify the digit present in the tenth place: 7
• Identify the next smallest place in the number: 3
• If the smallest place digit is greater than or equal to 5 then round up the digit.
• As the digit in the smallest digit is less than 5, the digit gets round down.
• So the final number is 0.7

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Frequently Asked Questions – FAQs

Q1

What is meant by rounding off?

Rounding off means a number is made simpler by maintaining its overall value intact but nearer to the next number. It is applied for whole numbers and for decimals at places of tens, hundreds, thousands, etc.

Q2

How does rounding off work for whole numbers?

Rounding rules for whole numbers are as follows:
To get an accurate final result, always choose the smaller place value.

• Look for the next smaller place, which is towards the right of the number that is being rounded off. For example, if you are rounding off a digit from the tens place, look for a digit in the one place.
• If the digit in the smallest place is less than 5, then the digit is left untouched. Any number of digits after that number becomes zero, and this is known as rounding down.
• If the digit in the smallest place is greater than or equal to 5, then the digit is added with +1. Any digits after that number become zero, and this is known as rounding up.

Q3

See Also

A Pocket Guide to Time Clock Rounding - Hourly, Inc.Use These Simple Rules to Round Numbers Quickly and CorrectlyWorkforce Management Software News, Blog, and ResourcesWhat Is Time Clock Rounding?

How to round off decimals?

Rounding rules for decimal numbers are as follows:

• Find the rounding digit and analyse it at its right-hand side.
• If the digits on the right-hand side are less than 5, consider them equal to zero.
• If the digits on the right-hand side are greater than or equal to 5, then add +1 to that digit and consider all other digits as zero.

Q4

Explain the process of rounding the nearest tenth?

Let’s consider the number 0.64. To round off to the nearest significant number, consider tenths place and follow the steps as given below:
Identify the digit present in the tenth place: 6
Identify the next smallest place in the number: 4
If the smallest place digit is greater than or equal to 5, then round up the digit.
As the digit in the smallest digit is less than 5, the digit gets rounded down.
So the final number is 0.6.

Q5

Define significant figures.

The significant figures of numbers are digits that convey the meaning that contributes to its measurement result.

Q6

Is rounding off important?

Yes, it is very important in calculations involving long decimal digits.

Test Your Knowledge On Error Significant Figures Rounding Off!

Q5

Put your understanding of this concept to test by answering a few MCQs. Click ‘Start Quiz’ to begin!

Select the correct answer and click on the “Finish” button
Check your score and answers at the end of the quiz

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See Also

Rounding Numbers - Rules & Examples For Fractions & Sums

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PHYSICS Related Links
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Comments

Leave a Comment

1. 

   Sayani Goon July 19, 2020 at 6:41 pm

   My concept was not cleared by reading the book but when l got these my concept was fully cleared and it was more understandable for me.

   Reply

2. 

   Nikhil Dubey August 11, 2020 at 2:13 pm

   If I have to round off 6.335001 in 3 SF then what is the answer?

   Reply

• 

  Deepa August 12, 2020 at 6:13 pm

  Rounding off 6.335001 to 3 SF we get 6.34

  Reply

Aamina July 4, 2021 at 3:19 pm

Thankyou

Reply

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