Rounding Off Numbers Lesson: Nearest Ten, Hundred, Thousand

Lesson Overview

• What Does Rounding Mean?
• Rounding Numbers to the Nearest Ten
• Rounding Numbers to the Nearest Hundred
• Rounding Numbers to the Nearest Thousand
• Rounding Numbers to the Nearest Ten Thousand
• Practice Problems for Rounding Numbers

Rounding off numbers is an essential mathematical skill that simplifies numbers, making them easier to use for calculations, comparisons, and estimations. By rounding, we can approximate a number to a specific place value, such as the nearest ten, hundred, or thousand. This process helps when exact precision is not necessary but a close approximation is required.

In this lesson, we will focus on rounding numbers to the nearest ten and nearest hundred, with an emphasis on rounding to the nearest thousand and ten thousand. You'll learn the rules for rounding and practice using them to round numbers efficiently.

What Does Rounding Mean?

Rounding is the process of adjusting a number to make it simpler while keeping it close to the original value. The main goal is to reduce the size of the number while keeping it as accurate as possible for practical purposes. For example, if you need to estimate the total cost of items when shopping, rounding the prices makes it easier to calculate.

There are two main steps to rounding:

1. Identify the place value you are rounding to (e.g., tens, hundreds, or thousands).
   
2. Look at the digit immediately to the right of that place value. This digit will determine whether you round up or down.
   

Rounding Numbers to the Nearest Ten

To round a number to the nearest ten, you need to focus on the ones digit (the last digit of the number). Here's how to do it:

Rounding Rules for the Nearest Ten:

1. If the ones digit is 5 or greater, round up. This means increasing the tens digit by 1 and changing the ones digit to 0.
   
2. If the ones digit is less than 5, round down. This means keeping the tens digit the same and changing the ones digit to 0.
   

Examples:

1. Rounding 25 to the nearest ten:
   The ones digit is 5, so we round up to 30.
   
2. Rounding 86 to the nearest ten:
   The ones digit is 6, which is greater than 5, so we round up to 90.
   
3. Rounding 214 to the nearest ten:
   The ones digit is 4, which is less than 5, so we round down to 210.
   

Take This Quiz:

Quiz : How Well Do You Know About Rounding Numbers?

Rounding Numbers to the Nearest Hundred

When rounding to the nearest hundred, focus on the tens digit (the second digit from the right). Here are the rules:

Rounding Rules for the Nearest Hundred:

1. If the tens digit is 5 or greater, round up. This means increasing the hundreds digit by 1 and changing the tens and ones digits to 0.
   
2. If the tens digit is less than 5, round down. This means keeping the hundreds digit the same and changing the tens and ones digits to 0.
   

Examples:

1. Rounding 537 to the nearest hundred:
   The tens digit is 3, which is less than 5, so we round down to 500.
   
2. Rounding 709 to the nearest hundred:
   The tens digit is 0, which is less than 5, so we round down to 700.
   
3. Rounding 455 to the nearest hundred:
   The tens digit is 5, which is equal to 5, so we round up to 500.
   

Rounding Numbers to the Nearest Thousand

Now, let's look at rounding numbers to the nearest thousand. This time, we focus on the hundreds digit (the third digit from the right).

Rounding Rules for the Nearest Thousand:

1. If the hundreds digit is 5 or greater, round up. This means increasing the thousands digit by 1 and changing the hundreds, tens, and ones digits to 0.
   
2. If the hundreds digit is less than 5, round down. This means keeping the thousands digit the same and changing the hundreds, tens, and ones digits to 0.
   

Examples:

1. Rounding 56,327 to the nearest thousand:
   The hundreds digit is 3, which is less than 5, so we round down to 56,000.
   
2. Rounding 87,099 to the nearest thousand:
   The hundreds digit is 0, which is less than 5, so we round down to 87,000.
   
3. Rounding 91,684 to the nearest thousand:
   The hundreds digit is 6, which is greater than 5, so we round up to 92,000.
   

Take This Quiz:

rounding to tens and hundreds quiz

Rounding Numbers to the Nearest Ten Thousand

Rounding numbers to the nearest ten thousand involves looking at the thousands digit (the fourth digit from the right). Follow the same rounding rules:

Rounding Rules for the Nearest Ten Thousand:

1. If the thousands digit is 5 or greater, round up. This means increasing the ten thousands digit by 1 and changing the digits to the right to 0.
   
2. If the thousands digit is less than 5, round down. This means keeping the ten thousands digit the same and changing the digits to the right to 0.
   

Examples:

1. Rounding 87,099 to the nearest ten thousand:
   The thousands digit is 8, which is greater than 5, so we round up to 90,000.
   
2. Rounding 50,999 to the nearest ten thousand:
   The thousands digit is 0, which is less than 5, so we round down to 50,000.
   
3. Rounding 214,842 to the nearest ten thousand:
   The thousands digit is 1, which is less than 5, so we round down to 210,000.
   

Take This Quiz:

Rounding Off Numbers (Assimilation)

Practice Problems for Rounding Numbers

Let's test your understanding of rounding numbers with a few practice problems:

1. Round 214,542 to the nearest ten thousand.
   
2. Round 5,675 to the nearest thousand.
   
3. Round 84,292 to the nearest hundred.
   
4. Round 56,380 to the nearest ten.
   
5. Round 4,759 to the nearest thousand.