How to Teach Double-Digit Addition With Regrouping (Carrying Made Simple)

Quick answer

To teach double-digit addition with regrouping, have your child add the ones column first. When that sum is 10 or more, they write the ones digit and carry the ten to the tens column. Then they add the tens column, including the carried ten. Most kids learn this in 2nd grade, and the key is understanding that 10 ones become 1 ten.

Double-digit addition with regrouping (also called carrying) is the step where kids move from simple column addition to the routine they’ll use for the rest of elementary math. The idea is short, but it takes practice to make it automatic. Below is how to teach it, step by step, with worked examples and the mistakes to watch for.

What is double-digit addition with regrouping?

Regrouping happens when a column adds up to more than 9. Since each place can only hold a single digit, you keep the ones digit in that column and move the extra ten to the next column on the left.

Take 47 + 26:

The ones column is 7 + 6 = 13.
13 is 1 ten and 3 ones.
You write the 3 in the ones place and carry the 1 to the tens column.
Then you add the tens: 1 + 4 + 2 = 7.
The answer is 73.

This skill is part of Common Core standard 2.NBT.B.5, where 2nd graders learn to fluently add and subtract within 100 using place-value strategies. Most kids are ready once they can add two-digit numbers without regrouping and understand that a number like 47 means “4 tens and 7 ones.”

The 4-step routine for double-digit addition with regrouping

This is the routine your child will use every single time. Walk through it slowly at first, and narrate the steps out loud until they stick.

Step 1: Stack the numbers by place value

Write the numbers so tens line up over tens and ones over ones. This matters because you’re adding each column separately.

Step 2: Add the ones column

Start with the ones. If the sum is 9 or less, write it in the ones place and move to the tens. If the sum is 10 or more, you regroup.

Step 3: Regroup when the ones column is 10 or more

When the ones add up to 10 or more, write the ones digit in the ones place and carry the ten to the tens column. Write the carried 1 small and above the tens column so you remember to add it in the next step.

Step 4: Add the tens column, including the carried ten

Add all the tens: the carried ten plus the tens from both numbers. Write the sum in the tens place.

Why “10 ones become 1 ten” is the key idea

The sentence that makes regrouping click is “10 ones become 1 ten.” When you have 10 or more ones, 10 of them bundle together into 1 ten, and that ten has to move to the column where tens live.

For kids who are confused, use base-ten blocks or 10 bundled straws. When the ones column adds up to 10 or more, have your child physically trade 10 ones for 1 ten and slide it to the tens column. Doing that with their hands turns carrying from an abstract rule into something they’ve seen happen.

The 3 mistakes kids make most (and how to fix them)

Hands-on ways to practice regrouping at home

Practice sticks when it’s short, real, and consistent. A few ideas:

Store math: add the prices of two items and check your answer against the receipt.
Dice addition: roll four dice, use two to build each two-digit number, and add them.
Game scores: keep a running total of points in a board game or card game.
Daily 5: five problems a day, every day, beats a long worksheet once a week.

Keep sessions to five or ten minutes. When your child gets one wrong, give a hint (“Did you add the carried ten?”) and let them try again before you show the answer. That second try is where the learning happens.

How to know your child has mastered regrouping

Your child is ready to move on when they can:

Add two two-digit numbers with regrouping quickly and accurately.
Explain why they carry (“10 ones make 1 ten”).
Solve a problem without needing to be reminded to add the carried ten.
Do simple word problems that use double-digit addition with regrouping.

When those feel solid, the natural next steps are double-digit subtraction with regrouping and three-digit addition, which use the very same column routine.

Free Double-digit Addition With Regrouping Worksheet

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The easiest way to give your child practice

For most parents, the hardest part isn’t teaching the routine. It’s coming up with enough of the right problems and keeping your child willing to do them. That’s where Octolearn helps: describe the skill (“double-digit addition with regrouping”), and it builds a grade-matched practice set with read-aloud support, a hint and a second try on every question, and stars that keep kids coming back. It’s free to try, and it takes the daily practice off your plate.

Frequently asked questions

What is regrouping in double-digit addition?

Regrouping (also called carrying) is what you do when the ones column adds up to 10 or more. You write the ones digit in that column and carry the extra ten to the tens column. For example, in 47 + 26, the ones make 7 + 6 = 13, so you write the 3 and carry the 1 ten to the tens column.

What grade learns double-digit addition with regrouping?

Most children learn double-digit addition with regrouping in 2nd grade, where it's part of Common Core standard 2.NBT.B.5 (fluently add and subtract within 100 using strategies based on place value). Some advanced 1st graders start it late in the year, but 2nd grade is when kids are expected to master it.

How do I explain carrying to my child?

Use the language "10 ones become 1 ten." When the ones column adds up to 10 or more, those 10 ones bundle together into 1 ten, which has to move to the tens column where tens belong. Base-ten blocks or bundled straws make this concrete: the child physically trades 10 ones for 1 ten and moves it over.

Why does my child keep forgetting to add the carried number?

Once the small 1 is written above the tens column, it's easy to skip. Have your child touch that carried digit and say it out loud first: "1 plus 4 plus 2." Saying it makes it harder to forget. Consistent practice with the same routine every time helps it become automatic.

What are good ways to practice regrouping at home?

Keep practice short and real: add prices from two items at the store, add scores in a game, or use dice to build random two-digit numbers. Five to ten problems a day beats a long worksheet once a week. Use base-ten blocks if your child still needs to see the regrouping happen, and always give a hint before showing the answer so mistakes turn into learning.