🔢 MathGrade 2Lesson 14
← Back🔒 PDF with full access

Add with Regrouping

Lesson preview: the Mini Lesson and Vocabulary are open to everyone. Guided practice, exercises, the parent checklist and the printable PDF worksheet come with full access (free 7-day trial or membership).

Learning Objectives

  • 1Add two 2-digit numbers that require regrouping
  • 2Write the carried ten above the tens column before adding
  • 3Identify additions that do not require regrouping
📘

Mini Lesson

When you add two numbers in a column and the answer is 10 or more, the ones column overflows. You regroup — carrying the ten into the tens column.

The four-step column method

  • Step 1 — Line up: Write both numbers one above the other, ones under ones and tens under tens.
  • Step 2 — Add the ones: Add the digits in the ones column. If the answer is 10 or more, write the ones digit below the line and carry the 1 (one ten) to the top of the tens column.
  • Step 3 — Add the tens: Add all digits in the tens column, including the carried 1.
  • Step 4 — Write the sum: Read the tens digit and ones digit together as your answer.

Worked example: 47 + 36

  • Ones: 7 + 6 = 13 — write 3 below, carry 1 to tens.
  • Tens: 4 + 3 + 1 (carried) = 8.
  • Sum: 83.

When do you NOT need to regroup?

  • If the ones column adds up to 9 or less, no carrying is needed — just write the ones digit below and add the tens normally.
  • Example: 32 + 25 → ones: 2 + 5 = 7 (no carry) → tens: 3 + 2 = 5 → sum = 57.
Column addition 47 plus 36 with regroupingA vertical column addition layout. 47 on top, 36 below, plus sign on the left, a line underneath. A small carried 1 sits above the tens column. Ones: 7 plus 6 equals 13, write 3, carry 1. Tens: 4 plus 3 plus 1 equals 8. Answer: 83.47 + 36 = ?TO147+3683Ones: 7+6=13 → write 3, carry 1Tens: 4+3+1=8 → Sum = 83
Column addition 47 + 36. Ones give 13 — write 3, carry 1 (red circle). Tens: 4 + 3 + 1 = 8. Sum = 83.
Regrouping decision: ones column 10 or more?A decision diamond: Do the ones add up to 10 or more? Yes branch leads to: write ones digit, carry 1 to tens. No branch leads to: write ones digit, no carry. Both branches show example sums.Ones column: 10 or more?Ones ≥ 10?YESWrite onesCarry 1NOWrite onesNo carry32 + 25: ones 2+5=7No carry → 5747 + 36: ones 7+6=13Carry 1 → 83Always add the ones column first!
A decision diamond — if the ones add up to 10 or more, carry 1; otherwise no carry. Two examples show both paths.
💡

Ask yourself: "Do the ones add up to 10 or more? If yes, carry a 1 to the tens column."

Vocabulary
Regrouping
Carrying a ten when the ones column adds to 10 or moree.g. Adding 47 + 36 needs regrouping.
Carry
To move a ten from the ones column to the tens columne.g. After 7 + 6 = 13, I carry the 1.
Column
A line of digits going up and down in place valuee.g. Line up the ones column under the ones.
Ones column
The right-most column where the ones digits goe.g. I added the ones column first.
Tens column
The column to the left of the ones, where tens digits goe.g. After carrying, I added the tens column.
Sum
The answer when you add numberse.g. The sum of 47 + 36 is 83.
Free · 7 days · No credit card

Unlock the full HSEA system for 7 days.

Add your first kid profile and your 7 days start: every lesson in every grade, saved progress for each child. Nothing to set up, no card required, nothing to cancel.

  • ✓ All 1,680 lessons, Grades 1–6, every subject
  • ✓ Profiles + saved progress for every kid
  • ✓ Printable lessons with answer key
Start your 7-day free trial →
Already convinced? See full membership plans →
← Lesson 13: Check Answers Using Inverse OperationsLesson 15: Subtract with Borrowing →