Try sofatutor for 30 Days

Discover why over 1.6 MILLION pupils choose sofatutor!

Adding and Subtracting Decimals

Do you want to learn faster and more easily?

Then why not use our learning videos, and practice for school with learning games.

Try for 30 Days

Learning text on the topic Adding and Subtracting Decimals

Adding and Subtracting Decimals

Welcome to the world of Adding and Subtracting Decimals! Today, we'll explore how to add and subtract decimal numbers using strategies based on place value. We'll ensure you understand this fundamental concept and feel confident in applying it!

Understanding Adding and Subtracting Decimals

Adding and subtracting decimals is the process of combining or taking away amounts that are represented in tenths, hundredths or even smaller units, by ensuring that the decimal points are aligned.

Adding decimal numbers and subtracting decimal numbers might seem tricky at first, but using your knowledge of place value and careful alignment of digits, it becomes like adding and subtracting with whole numbers, using methods that you are already familiar with.

Like with whole numbers, you always align the numbers by place value, making sure the decimal place is aligned too. You can use a place value chart to help you align your numbers correctly.

27591_ToV_Adding_and_Subtracting_Decimals-01.svg

If one of the numbers you are adding or subtracting has fewer digits in the decimal places, you can annex, or add, zeros to make the digits the same length. This helps with aligning for addition and subtraction.

Adding and Subtracting Decimals – Rules

If you are wondering how to add decimals or how to subtract decimals, you can follow step-by-step rules for each operation. Below are the rules for you to learn and follow.

Operation Step Description
Adding Decimals Step 1 Line up the decimal points of the numbers vertically.
Step 2 If necessary, add zeros to make the decimal parts equal in length.
Step 3 Add the numbers as you would with whole numbers.
Step 4 Bring the decimal point straight down into your answer.
Subtracting Decimals Step 1 Line up the decimal points of the numbers vertically.
Step 2 If necessary, add zeros to the end of the decimal part to make them equal in length.
Step 3 Subtract the numbers as you would with whole numbers.
Step 4 Bring the decimal point straight down into your answer.

Let’s check-in by answering some questions about what we have learnt so far!

What do you do if one decimal has fewer digits?
Why is place value important in this process?

Adding and Subtracting Decimals – Step-By-Step Examples

Let’s walk through a decimal addition example to make sure you understand the process of adding decimals. Let's solve: 3.75 + 2.6.

  • First, align the decimals, adding a zero in the hundredth place for 2.6:

27591_ToV_Adding_and_Subtracting_Decimals-02.svg

  • Then, add as you would with whole numbers, keeping the decimal point in the same place:

27591_ToV_Adding_and_Subtracting_Decimals-03_(1).svg

The answer for 3.75 + 2.6 is 6.35.

Now let’s walk through another example, this time for subtracting decimals. Let’s solve: 5.8 - 2.35.

  • First, align the decimals, adding a zero in the hundredths place for 5.8.

27591_ToV_Adding_and_Subtracting_Decimals-04.svg

  • Then, subtract as you would with whole numbers, keeping the decimal point in the same place:

27591_ToV_Adding_and_Subtracting_Decimals-05_(1).svg

Adding and Subtracting Decimals – Guided Practice

Now we will walk through an example together. Let's solve: 5.82 - 3.4.

What is the first step?
What is the next step?
What is the answer for 5.82 - 3.4?

Adding and Subtracting Decimals – Exercises

Now you are ready for some decimal addition and subtraction practice on your own! For the first problem solve 7.53 - 4.6.

What is 7.53 - 4.6?

For the next problem, solve 8.75 + 3.42.

What is 8.75 + 3.42?

Adding and Subtracting Decimals – Summary

You can use place value to add and subtract decimal numbers, by following these steps:

  • Align decimal points and ensure equal length by adding zeros.
  • Add or subtract as with whole numbers.
  • Remember the importance of place value for accurate calculation.
  • Always check your answer.

Practise these steps to build your confidence and skill in decimal addition and decimal subtraction.

Explore more about Adding and Subtracting Decimals with our interactive practice problems, engaging videos, and printable worksheets on our learning platform. Your journey in mastering decimals is just beginning! Check out videos on Adding Decimals using Place Value and Subtracting Decimals using Place Value for extra practice in this topic.

Adding and Subtracting Decimals – Frequently Asked Questions

Can I add or subtract decimals without aligning them first?
What if there are different numbers of digits after the decimal point?
Why do we add zeros in decimal subtraction?
How do I know where to place the decimal point in the answer?
Can I use these methods for decimals with more than two places?
Is it necessary to always write zeros after the decimal if there is no value?
Are there any tools to help with adding and subtracting decimals?
Can I use the same methods for both addition and subtraction of decimals?
Are there any common mistakes to watch out for when adding or subtracting decimals?
Can decimal addition and subtraction skills be applied in real-life situations?
Rating

Be the first to give a rating!
The authors
Avatar
sofatutor Team