QUICK LINKS


Introduction

QUICK LINKS


Introduction

Adding and Subtracting Decimals

INTRO
β€”
Think of adding decimals like adding beads to a necklace, and subtracting decimals like removing beads from a necklace.
We can have all sorts of wacky beads or charms, but no matter what, their holes have to line up in order to add and remove them!
Our decimal points are like the bead holes. We might have decimals of different lengths, but as long as we make sure to line up our decimal points, we’ll be able to add and subtract them up with no problem!
Try dragging the bottom decimal to line up the decimal points!
Check out our
Calculator
or explore our
Lesson
and
Practice
sections to learn more about adding and subtracting decimals and test your understanding.

You can also use the Quick Links menu on the left to jump to a section of your choice.

You can also use the Quick Links dropdown above to jump to a section of your choice.

CALCULATOR
β€”

Adding and Subtracting Decimals Calculator

Step 1. Line up the decimal points.

We have to line up the decimal points just like we have to line up the holes in beads to make a bracelet.
When we subtract a bigger number from a smaller number, our answer will be negative. To subtract, we swap the top and bottom, and add a negative sign where the answer goes:

Step 2. Add trailing zeros.

This step is optional, but we can add 's to the end of our shorter decimal to make adding & subtracting decimals easier.

Step 3. Add/subtract.

The decimal point in the final answer should line up with the other decimal points.
So, the answer is .
KEY STEPS
β€”

How to Add and Subtract Decimals

Step 1. Line up the decimal points.

We have to line up the decimal points just like we have to line up the holes in beads to make a bracelet.

Step 2. Add trailing zeros.

This step is optional, but we can add 's to the end of our shorter decimal to make adding and subtracting decimals easier.

Step 3. Add/subtract.

The decimal point in the final answer should line up with the other decimal points.
LESSON
β€” Adding and Subtracting Decimals

Adding and Subtracting Decimals

Adding and subtracting decimals is just like adding and subtracting whole numbers but with an additional twist: we have to make sure we line up our decimal points!
Try dragging the bottom decimal to line up the decimal points!
Once we do that, we can add trailing zeros to the ends of the decimals to line everything up without changing any values.

Trailing Zeros 🚢🏿🚢🏼🚢🏾

Trailing zeros are polite and never cut in the middle of a decimal. They always go at the end.
So we can do this:
βœ…
But we CANNOT do this:
⛔️
Adding trailing zeros can make it easier to add/subtract decimals:

When subtracting decimals, we also need to remember that the first number needs to be bigger than the second number.
If the second number is bigger, then we need to swap them to subtract with borrowing to find the difference.


Once we find the difference, we need to add a negative sign.In other words... minus is equal to the negative of minus , which is equal to .

How to Subtract with Borrowing

We use the borrowing method when the top digit in a column is smaller than the bottom digit in that column.

Step 1. "Borrow," or subtract, from the top digit in the column directly to the left.

Step 2. Add the in front of the digit we're working on.

Let’s take a look at some step-by-step examples!

EXAMPLE 1

Let's start by finding the answer to:

EXAMPLE 2

Nice work! Now, let's find the answer to:

EXAMPLE 3

Amazing job! Let's try one more slightly harder problem. Find the answer to:
Awesome! If you’d like to practice additional problems with adding and subtracting decimals, expand the
Practice
below before closing out this lesson! ⚑
PRACTICE
β€” Adding and Subtracting Decimals

Practice: Adding and Subtracting Decimals

Question 1 of 10:

Step 1. Line up the decimal points.

We have to line up the decimal points just like we have to line up the holes in beads to make a bracelet.

Step 2. Add trailing zeros.

This step is optional, but we can add 's to the end of our shorter decimal to make subtracting them easier.

Step 3. Subtract.


Great work! Our answer is .

CONCLUSION
β€”
Incredible job, look at you go! Thanks for checking out this lesson β˜ΊοΈπŸ™. Where to next?
Leave Feedback