In the context of adding two-digit numbers, what does the term "regrouping" mean?

Regrouping means taking a group of 10 from one place value (like 10 ones) and converting it into one unit of the next higher place value (like 1 ten). This is done when the sum of digits in a place value column is 10 or more.

When adding two-digit numbers, which place value column should you always add first?

You should always add the ones place column first.

If you add the digits in the ones place and their sum is 15, what number should you write in the ones place of your answer, and what should you do with the remaining amount?

You should write '5' in the ones place of your answer. The remaining '1' represents 1 ten, which should be regrouped (or carried over) to the tens place column.

Explain why you cannot simply write the number '12' in the ones place when the sum of the ones digits is 12.

You cannot write '12' in the ones place because each place value column can only hold a single digit (0-9). The number '12' represents 1 ten and 2 ones, so the '1' (representing a ten) must be moved to the tens place through regrouping.

Solve the following addition problem, showing your work and clearly indicating where regrouping occurs: 43 + 29

43 + 29 = 72. Steps: 1. Add the ones: 3 + 9 = 12. 2. Write '2' in the ones place of the answer. 3. Regroup the '1' (representing 1 ten) to the tens place. 4. Add the tens: 1 (regrouped) + 4 + 2 = 7. 5. Write '7' in the tens place of the answer. Result: 72.

Adding Two-Digit Numbers With Regrouping

Name: Adding Two-Digit Numbers With Regrouping
Author: Insta~Lesson

8th Grade · Math · 45 min

Lesson Preview

Learning Objective

I can add two-digit numbers using regrouping.

1
When adding two-digit numbers, you always start by adding the ones place, and if the sum is 10 or more, you need to regroup.
2
To regroup, you take 10 ones and group them together to make one ten, which is then added to the tens place.
3
After regrouping, you add the numbers in the tens place, including any carried tens, to find the final sum.

Related Lessons

Two-Digit Subtraction with Regrouping

Measuring Angles with a Protractor

No thumbnail

Quadric Surface Classification

Related Lessons

Two-Digit Subtraction with Regrouping

Measuring Angles with a Protractor

No thumbnail

Quadric Surface Classification

New to Insta~Lesson?

We would love to help you present Insta~Lesson to your colleagues and administrators. Here are a few resources you can use:

Adding Two-Digit Numbers With Regrouping

Lesson Preview

Learning Objective

Warm-Up Video

Key Concepts

Practice Questions

Exit Ticket

Related Lessons

Two-Digit Subtraction with Regrouping

Measuring Angles with a Protractor

Quadric Surface Classification

Related Lessons

Two-Digit Subtraction with Regrouping

Measuring Angles with a Protractor

Quadric Surface Classification

New to Insta~Lesson?

About Insta~Lesson

How Insta~Lesson Helps Teachers Plan

How Insta~Lesson Supports Instruction Schoolwide