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

Elementary

subject
Math
learning style
Visual
personality style
Beaver
Grade Level
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.

Listen to Rounding Numbers Song: Nearest Ten & Hundred by NUMBEROCK to see some examples:

 

Share the trick you learned in the song with a parent or teacher.

  1. On your own paper, draw the number line on the hill from the video. Fill in numbers 0 to 10. Make sure the 5 is at the top of the hill.
  2. Get a small plastic toy car. If you don't have a toy car, you could use a counter, a paper clip, or even your pencil.
  3. Move your car along the number line to round the number 324 to the nearest tens place.
  4. Tell your answer to a parent or teacher.

Did you round 324 to 320? Great work!

How to round 324:

  • Step 1 We are rounding to the tens place, so we look to the digit in the ones place.
  • Step 2 4 is less than five. We can move our car backwards on the number line and round down.
  • Step 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.

Use your number line to round 478 to the nearest hundreds place. Tell your answer to a parent or teacher.

Did you round up to 500? Fantastic!

How to round 478:

  • Step 1 We are rounding to the hundreds place, so we look to the digit in the tens place.
  • Step 2 7 is greater than five. We can move our car forward on the number line and round up.
  • Step 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?

Share your thoughts with a parent or teacher.

Then, try some more practice with rounding numbers in the Got It? section.

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