Using base-ten blocks to model a subtraction with regrouping, which operation is being illustrated?

Using base-ten blocks to model a subtraction with regrouping, which operation is being illustrated?

• A. Addition With Regrouping
• B. Subtraction With Regrouping
• C. Multiplication
• D. Division

Answer: (B)

Regrouping in subtraction shows up when the amount in the smaller place value isn’t enough to subtract. With base-ten blocks, you model this by borrowing from the next place value: you take one ten-block and turn it into ten unit blocks, adding them to the units so you can complete the subtraction. After you borrow, the tens value decreases by one, and the ones become large enough to subtract the needed amount. In practice, you might start with a situation where you have fewer units than you need to subtract, so you borrow from the tens, turning that ten into ten ones. Then you subtract in the ones column, and finally you adjust the tens column to reflect the borrow. This demonstrates subtraction with regrouping because the borrowing is part of performing subtraction with place-value awareness. This is distinct from addition with regrouping, which uses carrying to move values from one place to the next when adding. Multiplication and division aren’t about borrowing in this way during the operation. So the scenario with base-ten blocks is illustrating subtraction with regrouping.

Regrouping in subtraction shows up when the amount in the smaller place value isn’t enough to subtract. With base-ten blocks, you model this by borrowing from the next place value: you take one ten-block and turn it into ten unit blocks, adding them to the units so you can complete the subtraction. After you borrow, the tens value decreases by one, and the ones become large enough to subtract the needed amount.

In practice, you might start with a situation where you have fewer units than you need to subtract, so you borrow from the tens, turning that ten into ten ones. Then you subtract in the ones column, and finally you adjust the tens column to reflect the borrow. This demonstrates subtraction with regrouping because the borrowing is part of performing subtraction with place-value awareness.

This is distinct from addition with regrouping, which uses carrying to move values from one place to the next when adding. Multiplication and division aren’t about borrowing in this way during the operation. So the scenario with base-ten blocks is illustrating subtraction with regrouping.