How to Round With Decimals

Are you teaching your students how to round with decimals this year? If you need a quick refresher on this skill, check out our quick ‘How-To’ below!

Rounding with decimals is a bit like rounding with whole numbers, but we also pay attention to the decimal part. 

Understand Place Value – Start by explaining place value. In a decimal number, like 3.78, the ‘3’ is in the ones place, the “7” is in the tenths place, and the “8” is in the hundredths place. You can also show this using a place value chart with columns for ones, tenths, hundredths and so on.

Identify the Rounding Digit – Now, let’s say you want to round 3.78 to the nearest tenth. The ‘7’ in the tenths place is the digit we’re rounding to. This is our ‘rounding digit.’

Look at the Digit to the Right – Next, look at the digit to the right of the rounding digit. In this case, it’s the ‘8’ in the hundredths place.

Decide Whether to Round Up or Down – If the digit to the right (the hundredths digit) is 5 or greater, you round the rounding digit (the tenths digit) up. If it’s less than 5, you leave the rounding digit as it is. In our example, 8 is greater than 5, so we round the ‘7’ up to ‘8.’

Adjust the Rest of the Decimal – Now, you can drop all the digits to the right of the rounding digit to zeros. 

Put It All Together – So, rounding 3.78 to the nearest tenth, we get 3.8. The ‘7’ in the tenths place got rounded up to ‘8,’ and the ‘8’ in the hundredths place was dropped because a 0 is not needed at the end of a decimal.

Decimal Rounding Slide Deck

Teach Starter has put together a comprehensive slide deck and accompanying worksheet to help your students master the art of rounding decimals. In this slide deck, you will find teaching opportunities for:

• Rules of rounding (whole numbers and decimals)
• Rounding to the nearest whole number
• How to round to one decimal place
• How to round to two decimal places
• Using a place value chart to round
• Using a number line to round
• Rounding money
• Problem-solving

Easily Prepare This Decimal Rounding Resource for Your Students

If you are ready to use this teacher-created resource in your classroom, head on over to the green download button! Here, you will find the editable PowerPoint presentation, Google Slides presentation, and a quick-print PDF file for the worksheet. When selecting a Google Slides option, please note that you will first be prompted to make a copy of the resource to your personal drive before accessing it.

This resource was created by Brittany Kellogg, a Teach Starter Collaborator. 

Read on For More Rounding Resources!

Don’t stop there! We’ve got more activities and resources that cut down on lesson planning time:  

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