Are your students struggling with addition of large numbers? When I was in elementary school, standard algorithm was the only strategy taught for adding big numbers. But, there are so many ways to teach addition! Sharing a variety of addition strategies with students ensures that every student can find a method that works for them when adding large numbers.


Interested in learning strategies for subtracting multi-digit numbers? Check out this blog post!

Adding Big Numbers

In this post, I will share three of my favorite strategies for adding big numbers. I’ve provided pictures and step-by-step instructions below. But, if you would prefer a video tutorial, all three of these ways to teach addition are also shown in this video.

Addition Strategy #1: Partial Sums

This adding big numbers strategy is similar to the partial products strategy that is used when multiplying bigger numbers.


To solve problems involving addition of large numbers using this strategy:

  1. Line the addends up vertically by place value.
  2. Add the ones place. Write the entire sum below the equal. No numbers should be carried when using this addition strategy!
  3. Repeat the process for each place value. Write the place value’s sum under the previous place value’s sum. For example, the tens sum should be written under the ones sum, etc. Keep in mind that for each place value, you are adding the total value of each place value. In the example pictured above, you are NOT adding 4 + 7 for the tens place. You are adding 40 + 70 for the tens place.
  4. Add all of the totals to find the final sum.

BONUS TIP: Encourage students to write each place value in a different color. Then, they should write the sum for that place value in the same color. This will help students to stay organized when adding big numbers.

Addition Strategy #2: Expanded Form

This big number addition strategy is a great way to review place value and writing numbers in expanded form while you teach addition.


To solve problems involving addition of large numbers using this strategy:

  1. Write each addend in expanded form.
  2. Add by place value.
  3. Find the final sum by adding each of the place values together.

BONUS TIP: If there is any regrouping, add the like place values together first. In the example pictured above, it is easiest to add 700 + 130 first because they both have three digits. Then, add the remaining place values.

Addition Strategy #3: Counting On Using a Number Line

This strategy for adding large numbers provides another opportunity to review place value and expanded form as you teach addition.


To solve problems involving addition of large numbers using this strategy:

  1. Draw an open number line.
  2. Write the largest addend on the far left side of the number line.
  3. Add the largest place value from the other addend. Show that this place value was added by drawing a “jump” on the number line and writing the new total at the end of the jump.
  4. Repeat by adding each place value from the second addend. Each place value should be added one at a time.

BONUS TIP: Encourage students to draw jump sizes that are proportional to the place value they are adding. For example, the jump for the thousands place should be larger than the jump for the tens place. See the image above to get an idea of how each new jump will be slightly smaller. As you work on drawing jumps, discuss place value and comparing numbers.

Addition of Large Numbers Teaching Resources

I’ve just shared three of my favorite strategies for teaching addition of large numbers. I find that if a student is struggling with one strategy, showing them another way to add is often the key to their success.

If you’re looking for even more ways to teach adding big numbers, be sure to check out my Addition and Subtraction Units. Each unit shows six ways to teach addition and five ways to teach subtraction with bigger numbers.

Each unit also comes with everything you need to teach adding and subtracting. You’ll find:

  • Detailed lesson plans
  • Worksheets
  • Games and centers
  • Foldables and Sorts
  • Anchor charts
  • Exit tickets
  • Digital activities
  • Quizzes
  • Final Test

I have Addition and Subtraction Units for all upper elementary grade levels, covering every large number range that you might be teaching. These adding and subtracting lessons take the stress out of planning by providing everything you need with minimal prep work required.

I hope you find these adding strategies and resources to be helpful. Be sure to pin this post for later so that you can access these addition of large numbers strategies at any time!