Common Core: 2nd Grade Math

This subject covers foundational math concepts for 2nd graders, including addition, subtraction, and basic problem-solving skills.

Advanced Topics

Adding and Subtracting with Regrouping

What Is Regrouping?

Sometimes when you add or subtract, the numbers in the ones place add up to more than 9 or you need to borrow from the next place value. This is called regrouping.

How to Regroup in Addition

If you add 28 + 17, the ones (8 + 7 = 15) are more than 9. You keep the 5 in the ones place and carry over 1 to the tens place.

How to Regroup in Subtraction

If you subtract 42 - 19, you can't take 9 from 2. So you borrow 1 from the tens place (making it 3), and add 10 to the ones place (making it 12 - 9 = 3).

Why Regrouping Is Helpful

Regrouping helps you solve bigger problems and get the right answer every time!

Examples

  • 56 + 27: Add ones (6 + 7 = 13), regroup 1 ten, answer is 83.

  • 53 - 27: Borrow from tens, 13 - 7 = 6, answer is 26.

In a Nutshell

Regrouping helps you add and subtract numbers that go over 10 or need borrowing.

Key Terms

Regrouping
Moving values between place values to help add or subtract.