These worksheet focus on adding two three-digit integers together.

Adding a pair of triple digit numbers involves several different skills that we should have a handle on by now. It all begins with making sure everything is lined up and understanding the concept of place value. This page gives you access to worksheets that focus specifically on adding multiple 3 digit worksheets. That is really as simple as it gets for basic addition. You'll have lessons show you the process of the skill up close. We also have eight practice worksheets to give you more time on this skill. While a lot of teachers underestimate this skill, we feel it is a flagship skill that all the kids really need to master as soon as possible.

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Print Triple Digit Addition Worksheets

Click the buttons to print each worksheet and associated answer key.

Triple Digit Addition Worksheet 1

Triple Digit Addition - Worksheet 1

We use a sizable font and a nice barrier for you to work on this independently.

Worksheet 2

Worksheet 2

We maximized digit place carrying on this version. You should have plenty of space to stretch out your three digit patterns.

Worksheet 3

Worksheet 3

We minimized place carrying on this worksheet.

Triple Digit Addition Lesson

Triple Digit Addition Lesson

A full step-by-step analysis for you of adding 864 + 357. 1. Add the ones column place. 4 + 7 = 11. 2. Rename 11 as 1 + 1 (the 1 is placed over the tens column). 3. Add the tens column place. 6 + 5 + 1 = 12. 4. Rename 12 as 1 and 2(the 1 is placed over the hundreds column). 5. Add the hundreds column place. 8 + 3 + 1 = 12. 6. Bring down 1 from hundreds column.

Homework and Practice Worksheet

Homework and Practice

See a triple digit addition problem done for you and then cover the other two problems at the bottom.

Independent Practice Worksheet

Independent Practice

Another slab full of problems for you to handle well.

Independent Practice Worksheet 2

Practice the Skill Twice

A follow up worksheet to really hammer down this problem set.

Show the Skill Worksheet

Show the Skill

This will give 8 triple digit addition problems and see how you do with them. This should be called a show off page, but the next sheet is the real deal instead.

Triple Digit Addition Mad Minute Worksheet

Triple Digit Addition Mad Minute

A quarter of problems for you to work through in a timed environment. See how many you can get done correctly in a minute.

Warm Up Worksheet

Warm Up

A nice review or introduction worksheet based on where your kids stand on this. It consists of 3 triple digit addition problems for you to take in.

How to Add Triple-Digit Numbers

You may have mastered the concept; however, it may be hard for your students to understand. To break it down, triple-digit addition, or three-digit addition, is an equation which involves at least one three-digit addend.

Addition, within mathematics, can be defined as an operation through which one obtains a sum of at least two numbers.

Many genius minds around the world can add up three-digit numbers mentally. One of your students may be able to accomplish the same feat someday. For that, they will need to learn the rules used to calculate the results of three-digit addition.

Three-Digit Addition Rules

Before starting three-digit addition, you need to ensure the numbers you are adding are placed into their respective positions. This means that the ones need to be placed underneath the ones, the tens underneath the tens and so on.

For example, if you need to add 132 and 146, you need to first order them;

+ 146

This makes it easy to identify which numbers you need to add.

  • Start by placing the numbers in line with each other so as to reflect their positions.
  • Continue by starting from the right. First, add up the numbers that are the ones, and follow with the tens, ending with the hundreds.
  • When all the columns are finally added up, you are left with the sum. That is your final answer.

If you are not a genius yet, you may have to resort to a pen and paper and note down your sums to solve them. The addition of three-digit numbers can be done in one of two ways, i.e. with or without regrouping.

Without Regrouping

How to add triple-digit numbers without regrouping? Read ahead!

This is quite easy. All you need to do is add up the numbers, as explained earlier. Add up the individual digits in order, from right to left, to get their individual sums. Keep noting them down till you get to the final result.

Add 6 and 2 and note the result;

+ 146


Add 4 and 3 and note the result;

+ 146


Add 1 and 1 and note the result;

+ 146


Your sum is 278!

Here are some practice sums you can give your students to try out!

123 + 321

142 + 322

100 + 600

220 + 330

114 + 221

With Regrouping

How to add triple-digit numbers using regrouping? Let’s find out!

This method is a bit tricky. The need for this kind of addition arises when you need to carry forward or borrow. Simply put, this is when the sum of the two numbers is greater than 9. This leads to the need to carry forward the tens digit of the number to the next number in line.

For example, look at the sum below;


+  789

When you add the 9 plus 9 in the one's column, it leads to a sum of 18. In this case, we keep the 8 underneath the one column and carry forward the one above the ten’s column. Let's try it out.



+  789



Now we move on to the ten’s column. This time, we will not only add 8 and 3 but also include the one floating on top. This leads to the number 12. We repeat the same step here and take the one to float about the hundred’s column this time.



+  789



Finally, we have to add the numbers in the hundred’s column. We now add 8, 7 and 1 together. The result is 16, which makes the sum;



+  789



Final Thoughts

Addition is an important concept. It allows your students to advance to the next grade and learn how two things come together to result in a sum. This concept will stay with them throughout their lives and help them solve differential equations, matrices and much more!