Home›Lesson Plans›Mathematics›Number & Operations in Base Ten · Grade 3

Addition with Regrouping: When the Ones Overflow

Students add two numbers and discover what to do when a column adds up to more than nine — carrying a group of ten to the next place, the heart of multi-digit addition.

Grade 3Addition & Subtraction45 minutes1 class periodGradual ReleaseExplicit teaching4 StandardsCommon Core
Start the Lesson
Lesson at a Glance

Everything you need before the bell rings

Learning Objectives

Students will be able to…

  • ✓Add two-digit numbers with and without regrouping.
  • ✓Explain regrouping as trading ten ones for one ten.
  • ✓Line up numbers by place value to add.
  • ✓Check a sum using estimation.
Essential Question

When you add 47 + 38, the ones make 15 — too many to fit in one place. Where does that extra ten go?

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Lesson Phases
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Vocabulary Terms
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Standards Aligned
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Interactive Task
Model · Interactive Tool

The Regrouping Machine

Project this and change the two numbers. Watch the ones column, and see exactly when a ten has to be carried into the tens place.

➕ Add two numbers — watch the regroupTry it
First number47
Second number38

The Lesson · Gradual Release (I Do · We Do · You Do)

45 minutes, five moves

Tap any phase to open the teacher moves and student actions.

1

Launch — The Overflow

5 min

47 + 38: the ones make 15. Now what?

👩‍🏫 Teacher Moves

  • Write 47 + 38 stacked.
  • Add the ones — 15! Ask where the extra ten goes.
  • Set the goal: regrouping.

🎒 Student Actions

  • Add the ones and notice the problem.
  • Predict what to do with the extra.
  • Guess what “regroup” means.
2

I Do — Model the Carry

10 min

Teacher regroups step by step.

👩‍🏫 Teacher Moves

  • Add ones (15); write 5, carry 1 ten.
  • Add the tens plus the carried ten.
  • Name it: trading 10 ones for 1 ten.

🎒 Student Actions

  • Copy each step.
  • Show the carried 1 above the tens.
  • Say “write 5, carry the 1.”
3

We Do — Regroup Together

12 min

Class drives the Regrouping Machine.

👩‍🏫 Teacher Moves

  • Use the Machine with several pairs.
  • Compare regroup vs. no-regroup cases.
  • Predict the carry before it shows.

🎒 Student Actions

  • Call out numbers to add.
  • Predict whether it will regroup.
  • Write each sum with the carry.
4

You Do — On Your Own

13 min

Students solve with regrouping.

👩‍🏫 Teacher Moves

  • Assign a mix of regroup/no-regroup sums.
  • Add one subtraction-with-borrowing problem.
  • Have them estimate to check.

🎒 Student Actions

  • Solve the sums, carrying when needed.
  • Try one borrowing problem.
  • Estimate first to check reasonableness.
5

Close — Prove It

5 min

Solve the opener the standard way.

👩‍🏫 Teacher Moves

  • Return to 47 + 38.
  • Have students write the full algorithm.
  • Hand out the exit ticket.

🎒 Student Actions

  • Solve 47 + 38 = 85 with regrouping.
  • Explain where the carried ten went.
  • Complete the exit ticket.
Standards Alignment

Built to the standards you report on

Aligned to the Common Core State Standards for Mathematics, including the Standards for Mathematical Practice.

CCSS
3.NBT.A.2

Fluently add and subtract within 1000 using strategies and algorithms based on place value.

CCSS
4.NBT.B.4

Fluently add and subtract multi-digit whole numbers using the standard algorithm.

CCSS
3.OA.D.8

Solve two-step word problems using the four operations; assess reasonableness using estimation.

SMP
MP.6

Attend to precision when lining up place values and recording regrouping.

Differentiation

One lesson, every learner

Multilingual Learners

ELL / EMERGING READERS
  • Base-ten blocks to trade 10 ones for 1 ten.
  • Sentence frame: “The ones make ___, so I carry ___.”
  • Color-code the ones and tens columns.

Support & Access

IEP / 504
  • Provide place-value grid paper to align digits.
  • Start with no-regroup sums, then add regrouping.
  • Use blocks before the standard algorithm.

Stretch & Extend

GIFTED / EARLY FINISHERS
  • Add three two-digit numbers.
  • Solve subtraction with borrowing across a zero.
  • Add two three-digit numbers with two regroups.
Materials

What to gather

  • 📽️Projector / board
  • 📓Math notebooks
  • 💻The Regrouping Machine
  • 🧱Base-ten blocks
  • 📐Grid paper
  • 🎫Exit-ticket slips
Vocabulary

Key terms — hover for a quick definition

regrouptrade 10 of one place for 1 of the nextcarrymove a regrouped ten up a columnborrowregroup down for subtractionsumthe answer to additiondifferencethe answer to subtractionplace valuethe value a digit has by its placecolumna vertical line of digitsestimatea close, rounded guess
Evaluate

Exit Ticket

Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.

QUESTION 1
Add 56 + 27. Show whether you needed to regroup.
83 — yes: the ones (6 + 7 = 13) overflow, so carry 1 ten (write 3, carry 1); 5 + 2 + 1 = 8.
QUESTION 2
When the ones column adds up to 12, what do you do?
Write the 2 in the ones place and carry the 1 (one ten) into the tens column.
QUESTION 3
Estimate 48 + 33 by rounding to the nearest ten. Is your exact answer close?
About 50 + 30 = 80; the exact answer is 81, which is close — so it’s reasonable.

Going deeper? Play “Regroup or Not?”

Students draw two number cards, predict whether the sum will regroup, then solve to check — fast fluency practice. A printable card set and score sheet are in the Math library.

Study · Flashcards

Study the key terms

Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.

🃏 Multi-Digit Addition & SubtractionFlip
Card 1
Term
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Meaning
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Practice · Quiz

Check your understanding

A quick self-check with instant feedback, drawn from this lesson’s key terms.

📝 Multi-Digit Addition & SubtractionQuiz
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Question 1
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Practice · Worksheet

Printable worksheet

A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.

🖨️ Multi-Digit Addition & SubtractionPrint
Name: ________________________
Date: ____________

Part A · Write the word that matches each meaning

Word bank: borrow, carry, column, difference, estimate, place value, regroup, sum
  1. the answer to addition
  2. the value a digit has by its place
  3. regroup down for subtraction
  4. move a regrouped ten up a column
  5. a close, rounded guess
  6. trade 10 of one place for 1 of the next
  7. a vertical line of digits
  8. the answer to subtraction

Part B · Show what you learned

  1. Add 56 + 27. Show whether you needed to regroup.
  2. When the ones column adds up to 12, what do you do?
  3. Estimate 48 + 33 by rounding to the nearest ten. Is your exact answer close?
Answer key — Part A: 1) sum · 2) place value · 3) borrow · 4) carry · 5) estimate · 6) regroup · 7) column · 8) difference
Part B: 1) 83 — yes: the ones (6 + 7 = 13) overflow, so carry 1 ten (write 3, carry 1); 5 + 2 + 1 = 8. 2) Write the 2 in the ones place and carry the 1 (one ten) into the tens column. 3) About 50 + 30 = 80; the exact answer is 81, which is close — so it’s reasonable.