# Rounding Numbers

Contributor: Rachel Lewis. Lesson ID: 12177

Which is easier to add: 489 + 746 or 500 + 750? Sometimes, it's better and acceptable to round numbers to make math easier! You'll get plenty of practice as you round the bend on this math roundup!

categories

## Whole Numbers and Operations

subject
Math
learning style
Visual
personality style
Beaver
Intermediate (3-5)
Lesson Type
Skill Sharpener

## Lesson Plan - Get It!

Audio:

Quick!

• What is 478 rounded to the nearest hundred?

We’ll find the answer on our journey to rounding numbers to the nearest tens and hundreds place. We may even find some shortcuts along the way!

• How do we round numbers?

You can use place value to round numbers to the nearest tens and hundreds place!

To round a number to the nearest ten, you will need to look at the digit in the ones place.

If the digit is less than 5, you will round down by keeping the digit in the tens place the same.

If the number is 5 or greater, then you will round up by adding 1 to the digit in the tens place. You will have a zero in the ones place.

You can use the same method to round to the nearest hundred. Instead of looking at the digit in the ones place, you will look at the digit in the tens place.

If the digit is less than 5, you will round down by keeping the digit in the hundreds place the same.

If the number is 5 or greater, then you will round up by adding 1 to the digit in the hundreds place. You will have a zero in the tens and ones place.

Watch Rounding to Tens on a Number Line, by Alex Lochoff, to see some examples:

• Are you ready to use the trick you learned in the video?

1. On your own paper, draw the number line with a hill from the video. Fill in numbers 0 to 10. Make sure the 5 is at the top of the hill.
2. Find something to use like the ball in the video. Some ideas might be a counter, a paper clip, or even your pencil.
3. Move your item along the number line to round the number 324 to the nearest tens place.
• Did you round 324 to 320?

Great work!

Here is how to round 324:

1. We are rounding to the tens place, so we look to the digit in the ones place.
2. 4 is less than five. We can move our item backwards on the number line and round down.
3. If we round down, we keep the number in the tens place the same. The number in the ones place is 0.

324 rounded to the nearest tens place is 320.

Next, use your number line to round 478 to the nearest hundreds place.

• Did you round up to 500?

Fantastic!

Here is how to round 478:

1. We are rounding to the hundreds place, so we look to the digit in the tens place.
2. 7 is greater than five. We can move our item forward on the number line and round up.
3. If we round up, we add 1 to the number in the hundreds place. The number in the tens and ones place is 0.

478 rounded to the nearest hundreds place is 500.

• Do you think that rounding is an important skill? Why or why not?

When you are ready, try some more practice with rounding numbers in the Got It? section.

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