Solve the following addition problem: 345 + 287. Show your work, including any regrouping.

632. The student's work should demonstrate regrouping in the ones and/or tens place.

Explain in your own words why we sometimes need to 'regroup' when adding three-digit numbers. Use an example to help illustrate your explanation.

Regrouping is necessary when the sum of digits in a place value column (ones, tens, hundreds) is greater than 9. Since each place value can only hold a single digit (0-9), we must regroup the excess into the next higher place value. For example, in 256 + 167, adding the ones (6+7) equals 13. We can't put 13 in the ones place, so we regroup 10 ones as 1 ten, leaving 3 in the ones place and adding the 1 ten to the tens column.

Adding Three-Digit Numbers

4th GradeMath30 min

Learning Objective

I can add three-digit numbers with and without regrouping.

Lesson Flow

Watch Video

8 min

3 Digit Addition with Regrouping

Mrs. Montgomery's Learning Corner

Guided Notes

6 min

Key concepts students will learn:

•
When adding three-digit numbers with regrouping, it is important to line up the numbers in a place value chart.
•
If the sum of the digits in a place value is greater than 9, you must regroup by moving a group of 10 to the next place value.
•
In the example from the video, 235 + 475 = 710, and 789 + 185 = 974.

Practice

10 min

3 questions • Multiple choice & Short answer

Exit Ticket

5 min

“Solve the following addition problem. Make sure to show your work, including any regrouping: 357 + 265 = ?”

Teacher Guide

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Answer keys for all questions
Differentiation strategies
Extension activities
Printable student handouts

Adding Three-Digit Numbers

Learning Objective

Lesson Flow

Watch Video

Guided Notes

Practice

Exit Ticket

Teacher Guide

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